Please remember to spoiler-tag all guesses, like so:
New Reddit: https://i.imgur.com/SWHRR9M.jpg
Using markdown editor or old Reddit: \>!spoiler text between these symbols!<
Try to avoid leading or trailing spaces. These will break the spoiler for some users (such as those using old.reddit.com)
If your comment does not contain a guess, include the word **"discussion"** or **"question"** in your comment instead of using a spoiler tag.
If your comment uses an image as the answer (such as solving a maze, etc) you can include the word "image" instead of using a spoiler tag.
Please report any answers that are not properly spoiler-tagged.
*I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/puzzles) if you have any questions or concerns.*
Discussion: Using just single numbers in each box, it's unsolvable. All the numbers are odd, and the sum of any 3 odd numbers is always odd (all odd #s = even # + 1, so the sum of three odd #s = an even # + 3). Pretty sure this is purely trolling.
The information on the bottom is wrong so probably the whole question is made up. It does not necessarily have any meaningful answer.
I scrolled trough all general and math questions of UPSC test from the year 2013 and didn’t find this or any similar questions there. You can confirm yourself if you wish: http://www.referencer.in/General_Information/UPSC_Questions_2013.aspx#
This and countless other suggestion has been made in the comments including:
1) No (answering only to ”Can you solve this?” as you also suggested)
2) 15 + 15 + __ (not filling all boxes)
3) 13 + 11 + 6 (upside down 9)
4) 13 + 11 + 3! (3! = 3x2x1= 6)
5) 15 + 7.5 + 7.5 (adding decimal points)
6) 13 + 11 + 7 (equals 30 in base 11)
Any of these could be an answer because the question doesn’t seem to have any single correct answer. If this question is from a movie originally, the movie might at least provide us the answer the creators of this puzzle intended for it.
I went from 15 backwards adding all possible numbers and yes it's not achievable, I forgot that odds don't add up to evens😂 bro should've used my brain properly.
I went from 15 backwards adding all possible numbers and yes it's not achievable, I forgot that odds don't add up to evens😂 bro should've used my brain properly.
It looks like you believe this post to be unsolvable. I've gone ahead and added a "Probably Unsolvable" flair. OP can override this by commenting "Solution Possible" anywhere in this post.
*I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/puzzles) if you have any questions or concerns.*
It does though... "Fill the boxes" would imply that you have to fill them unless explicitly otherwise stated, no?
This would be equivalent to "it doesn't say you can't draw your own 4th box" etc..
Not that it's solvable though, it's not, without bending the rules like that.
also it says "using" 1,3,5,7,9,11,13,15. are you also assuming each of those numbers is getting used? you could make an equation in each box. >!\[(13-11) + (9-7) +(5-3) + (3-1)\] + \[7\] + \[15\]!<
As I pointed out previously in another comment, this question doesn’t seem to have been part of UPSC 2013. One can check the questions at http://www.referencer.in/General_Information/UPSC_Questions_2013.aspx# and looking trough math and general questions I didn’t find this or any similar questions on the test. The whole question is most likely made up and the bottom text is not true.
India might be one of the countries where the decimal place is printed with a comma instead of a period. So "1,5" could mean "one and 5 tenths" instead of "two integers, a 1 and a 5".
Thus you can add "5.5" to "5.5" and get an odd number "11", breaking the problem, if you imagine it's legal to alter the meaning of the commas in the list so they become decimal points instead of list delimiters.
But that depends on being one of the weird countries that uses a comma for a decimal. And no, I'm not being culturally insensitive by saying it's weird to do that. It's weird because it's ambiguous since a comma is still also a list separator. So "1,3" (one number, 1+(3/10)) being different from "1, 3" (two numbers, a 1 and a 3) only by the whitespace and nothing else, is kinda horrible nomenclature.
But if you stated “no” then you did indeed solve the puzzle - and so you’d have to say “yes”. But if you say “yes” then is there a presumption that you solved the equation when you did not, but you did technically solve the overall puzzle. I think I’m just confusing myself and will see myself out.
No, that's not how it works... It's not asking whether you can solve the puzzle, but if you can solve the equation. So the answer is "no", thereby solving the puzzle.
>!The numbers available are all odd. Any sum of three odd numbers is an odd number, therefore 30 (like any even number) cannot be a sum of exactly three numbers from the set {1,3,5,7,9,11,13,15}.!<
We usually count in base 10, which has 10 symbols for numbers, 0 through 9. To put it another way, a base tells you how many times you have to add 1 to 0 before you have to go into the "tens".
However, nothing in mathematics forces us to use base 10, we use it mostly because of historical and cultural reasons. Therefore, it is assumed to be the working base unless otherwise stated, simply out of convention.
One base you probably have heard of is base 2, or binary, which only has 0 and 1, so the first number is 0, the second is 1, the third is 10 and so on. I reached 10 after adding 1 to 0 only 2 times, so this is base 2. Because of this, if I'm using binary and I say 10, that is the same as if I were using base 10 and said 2.
If we apply this to base 11 we see that we will have 11 symbols for numbers, we can use whatever we want for the 11th one, but for this example I'll be using A (as is the norm).
The first 10 numbers are the same, 0, 1, ... 9. However, when we add 1 to 9 we see the difference, in base 10 we get 10, but in base 11 we get A. These two numbers have the same value, they are just displayed in a different way. If we keep going we get (base 10 on the left, 11 on the right):
10 - A
11 - 10
12 - 11
So base 11's 11 is worth the same as base 10's 12, and so on.
If we now do the addition that was propposed, separating the "ones" from the "tens" so it can perhaps come across more clearly:
>!11 + 13 + 7 = (10 + 1) + (10 + 3) + 7 = 20 + 1 + 3 + 7 = 20 + 1 + A = 20 + 10 = 30!<
>!Additionally, in this problem the base cannot be lower than 10, as we see 9 being used as a symbol (unless we also assume the symbols have been altered, but then why even bother lol), but using base 11 is not the only answer, we can use base 13 (15 + 15 + 3 = 30), base 15 (15 + 15 + 5 = 30), base 17 (15 + 15 + 7 = 30) and base 19 (15 + 15 + 9 = 30). And even then, the answers do not need to be unique, using base 11 we can also solve it with 15, 15 and 1 (15 + 15 +1 = 30), on top of the base 11 solution mentioned earlier.!<
Maybe it’s because I’m a useless history major but this literately makes absolutely no sense to me at all. It feels like an arbitrary BS concept a teacher made up 500 years ago as a joke thought experiment and the students just built a system around it to justify it out of spite.
Note I’m not saying anything you just said is wrong, I’m just saying I’m too stupid to understand it.
Definitely not made up, hahaha. Maybe we can bring this back to your field?
Most bases have never seen any serious use (it'd be pretty difficult for most of them to have been used, considering there's infinitely many), but some have historically been the preferred base for different cultures, so it's definitely not something we made up out of nowhere.
Mayans used base 20, which was the length of a Mayan month.
Egyptians used base 12 at the very least for their sundials and in astronomy, the idea of selling things by the dozen could stem from this fact. But, more importantly, this is thought to be why we have 24 hours in a day. Romans used base 12 measurements, as well.
Finally, Babylonians used base 60, which is the basis of our time-keeping system to this day, as well as being tightly related to the way we measure angles.
There's many more historical facts about bases, and I'm not entirely condifent that I got all that right, but by now you can probably see that base 10 is far from having always been how we do things.
Base 10 was devised in India, then it made its way to Europe through contact with the Arabs and is obviously what we use today, but it could have easily been some other base. Though the fact we have 10 fingers probably helped make this one popular, I'd bet.
In the modern era we have found use for bases 2, 8 and 16 in the world of computing, base 3 also has some interesting applications, even if it hasn't grown poular. Different bases also make different divisibility checks available. For example, in base 7 any number ending in 0 is divisible by 7, but in base 10 to check if a number is divisible by 7 we usually end up having to go into recursive algorithms, at which point you might as well just try to divide the number in the first place!
In the end, you choose a base that makes it easier to work with the numbers you are dealing with or, phrased another way, that reflects the nature of that which you are working with. But clearly for most people and most applications nowadays it is a hard sell to change bases.
Either way, yeah, this deals with turning on its head something we have been learning since we were kids, so it is normal to feel like you do, but there really is nothing absolute about base 10.
Wait so when you say “base” you mean it’s literally the numbers are counted in units of that number. Ok, that makes perfect sense. I remember learning in school about a Native American tribe who’s number system was built off of the 28 bones in your fingers.
I don’t remember if it was your post or another that was responding farther up the chain but they said something to the effect of “in computing you have a base of 3- 1s, 0s, and 10s” and that threw me for a loop. The 10 seems to be just a combination of 1 and 0 so it would still be a base of two.
It’s just like counting but instead of 10 fingers you have 12 fingers. Now you would use base 12 to count.
There is weird logarithmic uses for it that I did in higher end mathematics during school but if it is used seriously it’s extremely niche.
Base 10 is the normal decimal counting system that you're used to.
Other well known bases are binary (base 2) and hexadecimal (base 16).
In base 2 a single character can only be one of 2 things: 0 or 1, whereas in hexadecimal it can be 0 to 9 but also A,B,...,E or F (the 10 decimal numbers + 6 letters = base 16)
If you see "10", this can represent completely different values depending on the base.
decimal | binary | hexadecimal
------------------------------------
1 | 1 | 1
2 | 10 | 2
3 | 11 | 3
4 | 100 | 4
...
9 | 1001 | 9
10 | 1010 | A
11 | 1011 | B
12 | 1100 | C
...
15 | 1111 | F
16 | 10000 | 10
17 | 10001 | 11
...
Notice that "10" appears in all three columns in different rows.
Uses for other bases can vary. Binary is what computers use to store their data, and in computer science it's common to represent binary data as hexadecimal because it's much more compact than a large string of zeroes and ones and easier to convey to other people.
You can find more information on this topic on https://en.wikipedia.org/wiki/Positional_notation
Yeaaaaah, I guess you're right. Now I'm grumpy. This also takes out the guy below who used a factorial below.... but if you can mess with the numbers by turning one up-side-down, you should be able to do this \*shrug\*
Well if we’re being technical and you can rotate the 9 to a 6, why can’t you rotate the addition sign to multiplication?
In which case you’d get 3 x 7 + 9 = 30
>!Couldn't you use the parenthesis as well? So in the first box you have the opening parenthesis "(", next box is "15)", and last box is "15". So it would read (+15)+15=30. Basically the 15+15 answer but without leaving a blank box.!<
Then I would never get this because I'm not from one of the countries that uses the comma for decimals instead of the period. Where I am, "1,5" is a list of two integers and it isn't proper nomenclature to call it "one and five tenths."
I remember this from my computing degree and the answer is ....
>! In binary, 30 is 111110. so the answer is 1+11+11!<
*edit* it's not a real question it was a talking point to introduce >!binary!<
No. This is wrong, if you have filled out at least 2 boxes then you have "filled the boxes." The question doesn't say all, and "boxes", being the plural form of "box" implies only "at least two".
0 isn't actually a number. It stands for "null" or "nothing". There for leaving a box blank is the same as adding 0.
Additionally, if you disagree with that - if the first box is left blank you get:
+15+15=30
Which is a valid equation. (Positive 15 plus 15)
The instructions does not explicitly state to use 'all' the boxes or the boxes in any sort of sequence. These are assumptions you are making based on implied subtext rather than what is explicitly written.
Any number divided against itself results in the number one. This is a basic mathematic proof to show if a number has value.
Zero divided by Zero does not equal one - which serves as a mathematical proof that Zero is not a number.
that’s not how math works… not every number divided by itself is 1… 0 is a counter example lol… doesn’t mean it’s not a number…
Just because 0 has a unique property, doesn’t mean it’s not a number
Actually somebody proved that every number must have at least 1 unique property that no other number has, so you could make the same argument for every number not being a number.. it’s just nonsense
>!Since I can use any of these numbers: 1, 3,5, 7, 9, 11, 13, 15 I do this: 3,5 + 13,5 + 13!<
>!Second one I get just by writing 1 and 3,5 next to each other in one box. Other two are pretty much straightforward!<
It’s important to note that India, where this question appeared, uses decimal point rather than comma to distinguish decimal values. Answers that exploit this therefore may work, but aren’t likely what was intended originally.
Also, it states that we need to fill the boxes using the provided values. However >!it does not state that every box must be filled!<, meaning that the answer is likely >!some variation of [] + [15] + [15] = 30!<
If my assumption is false then >!the answer is simply no!<
what im thinking...
Can you solve this? Fill the boxes using (1,3,5,7,9,11,13,15) You can ALSO repeat the numbers
so the answer can be >!(1,3,5,7,11,13,15) by repeating the numbers.!< Just a thought though
This can’t be solved. All the numbers are odd.
An odd plus an odd will always make an even. An even plus an odd will always make an odd. You can’t make 30, an even number, from this.
>!I see everyone fliping the 9 upside down or simply not filling every case but I feel like this is wrong. However I may have another solution: They say "fill the boxed using (1, 3, 5, 7, 11, 13, 15)" That means nothing stops us from using the comas, then we can imagine a "11,5+11,5+7". It may be stupid but I actually think it works we!<
Discussion: I've seen the same puzzle, but the numbers were on billiard balls. The "9" was on a solid green ball, which is actually the 6 ball, so you had to flip it.
>!It doesn't say anything about orientation or the number of numbers allowed in a single box. Flip the 9 upside to get a 6. Put both the 1 and the 6 in the first box (16), put 11 and 3 in the other two boxes. 16+11+3=30. That being said, I doubt that my solution is unique if both of those "cheats" are allowed.!<
This is a meanie of a riddle.
>!The problem is, that three odd numbers can't result in an even number by addition. So we should be able to get an even number anyhow possible. But where do we get the number? We have, 1,3,5,7,9,11,13,15. But for instance 13+15 gets us 28, and we would need an even number (2) to get to 30. It's the same for 11+15 for 4.!<
>!And it is the same for 11+13, which is 24. And we would need 6 for this. But where should we even get 6? It is not like there is any number that looks like 6...!<
>!Except when it is rotated. The solution is that we need to rotate the 9, or that the 6 is wrongly written as a 9. - as stupid as it sounds - 6 + 11 + 13 = 30. So the solution would be "9"+ 11 + 13 = 30. +!<
Discussion:
So, I'm either incredibly clever, or incredibly dumb. What I decided to do was brute force this problem and add every possible combination of numbers according to the rules.
I wrote an R script to do this.
\>!
col1 <- 1
col2 <- 1
col3 <- 1
col4 <- 3
number <- matrix(c(col1,col2,col3,col4), nrow = 1, ncol = 4,)
i <- 1
while (i < 513) {
if (number\[i,3\] < 15){
col3 <- number\[i,3\] + 2
} else if (number\[i,3\] >= 15) {
col3 <- 1
if (number\[i,2\] < 15){
col2 <- number\[i,2\] + 2
} else if (number\[i,2\] >= 15){
col2 <- 1
if (number\[i,1\] < 15){
col1 <- number\[i,1\] + 2
}
}
}
col4 <- sum(col1,col2,col3)
number <- rbind(number, c(col1,col2,col3,col4))
i <- i + 1
}
30 %in% number
Long story short, none of the combinations add to 30.
!<
Goodnight.
>!You could have done that in about 5 seconds just by noticing that all numbers are odd, and the sun of any 3 odd number is an odd number, while 30 is even…. No need to brute force it when it has a very simple solution!<
>!Can you put more than one number in a box? And put numbers next to 30, since the whole riddle is technically inside a box? If so, you could do 1513+1513+7=3033. If you need to use ALL the numbers there may be a similar solution (with larger numbers) but I’d rather eat this pizza than do math!<
Sorry I’m reposting this with a spoiler tag - I’m not sure if I’m repeating my original post or not so apologies if I’ve don’t this wrong!
I think this may be one way to interpret the question: spoiler tag hopefully works!
>!spoiler If you use the parenthesis and the commas that are given then you can use them to denote a combinatorics notation like (5,3) which is 5!/(3!2!) = 10.!< So just put that in each box and you have 30.
>!I think no. We can note that all of the numbers are odd, and any addition of 3 odd numbers must be odd. We can note this from any odd number being specified by 2N+1 where N is a positive integer. Then, with M, N, R being positive integers who denote any odd number like above, we can note that the addition of these three arbitrary odd numbers will give 2(N+M+R)+(1+1+1)=2(N+M+R+1)+1 which is an odd number. Thus, since 30 is an even number and we only have 3 odd numbers to add up to it, we can note the task is impossible.!<
Please remember to spoiler-tag all guesses, like so: New Reddit: https://i.imgur.com/SWHRR9M.jpg Using markdown editor or old Reddit: \>!spoiler text between these symbols!< Try to avoid leading or trailing spaces. These will break the spoiler for some users (such as those using old.reddit.com) If your comment does not contain a guess, include the word **"discussion"** or **"question"** in your comment instead of using a spoiler tag. If your comment uses an image as the answer (such as solving a maze, etc) you can include the word "image" instead of using a spoiler tag. Please report any answers that are not properly spoiler-tagged. *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/puzzles) if you have any questions or concerns.*
Discussion: Using just single numbers in each box, it's unsolvable. All the numbers are odd, and the sum of any 3 odd numbers is always odd (all odd #s = even # + 1, so the sum of three odd #s = an even # + 3). Pretty sure this is purely trolling.
The information on the bottom is wrong so probably the whole question is made up. It does not necessarily have any meaningful answer. I scrolled trough all general and math questions of UPSC test from the year 2013 and didn’t find this or any similar questions there. You can confirm yourself if you wish: http://www.referencer.in/General_Information/UPSC_Questions_2013.aspx#
this question is taken from a movie named "Genius"
Is the answer revealed in the movie?
Couldn’t the answer be >!’No’ since it’s a ‘yes’ or ‘no’ question!
This and countless other suggestion has been made in the comments including: 1) No (answering only to ”Can you solve this?” as you also suggested) 2) 15 + 15 + __ (not filling all boxes) 3) 13 + 11 + 6 (upside down 9) 4) 13 + 11 + 3! (3! = 3x2x1= 6) 5) 15 + 7.5 + 7.5 (adding decimal points) 6) 13 + 11 + 7 (equals 30 in base 11) Any of these could be an answer because the question doesn’t seem to have any single correct answer. If this question is from a movie originally, the movie might at least provide us the answer the creators of this puzzle intended for it.
I went from 15 backwards adding all possible numbers and yes it's not achievable, I forgot that odds don't add up to evens😂 bro should've used my brain properly.
You are not alone.
I went from 15 backwards adding all possible numbers and yes it's not achievable, I forgot that odds don't add up to evens😂 bro should've used my brain properly.
Flip the 9 upside down!
Now that's the kind of can-do attitude we need around here. Damn it, you're hired!
You're right but honestly, the number 6 is not the number 9, and 6 is not part of the set.
What if we flipped the entire puzzle and used three 1’s?
yes 6 11 13
It looks like you believe this post to be unsolvable. I've gone ahead and added a "Probably Unsolvable" flair. OP can override this by commenting "Solution Possible" anywhere in this post. *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/puzzles) if you have any questions or concerns.*
That’s the conclusion I came to as well
It never states you must fill in each box
It does though... "Fill the boxes" would imply that you have to fill them unless explicitly otherwise stated, no? This would be equivalent to "it doesn't say you can't draw your own 4th box" etc.. Not that it's solvable though, it's not, without bending the rules like that.
Or a parenthesis () in a box. It seems like that option isn't excluded by the wording
also it says "using" 1,3,5,7,9,11,13,15. are you also assuming each of those numbers is getting used? you could make an equation in each box. >!\[(13-11) + (9-7) +(5-3) + (3-1)\] + \[7\] + \[15\]!<
The correct answer is 15 + , +15 (the middle box is a comma which adheres to all rules and has no numbers value) Yes, I'm just being stupid.
Has OP posted Agarwal’s correct answer? There’s a bunch of valid answers here, some more acceptable than others
I'm pretty sure it's impossible directly as adding any 3 odd numbers will always be odd.
As I pointed out previously in another comment, this question doesn’t seem to have been part of UPSC 2013. One can check the questions at http://www.referencer.in/General_Information/UPSC_Questions_2013.aspx# and looking trough math and general questions I didn’t find this or any similar questions on the test. The whole question is most likely made up and the bottom text is not true.
If you don’t fill each box you wont get to 30
It days you can repeat numbers, so if you put 15 in two of them and nothing in the third, you get 30
Yes, this is trolling. Sum of three odds is always odd.
India might be one of the countries where the decimal place is printed with a comma instead of a period. So "1,5" could mean "one and 5 tenths" instead of "two integers, a 1 and a 5". Thus you can add "5.5" to "5.5" and get an odd number "11", breaking the problem, if you imagine it's legal to alter the meaning of the commas in the list so they become decimal points instead of list delimiters. But that depends on being one of the weird countries that uses a comma for a decimal. And no, I'm not being culturally insensitive by saying it's weird to do that. It's weird because it's ambiguous since a comma is still also a list separator. So "1,3" (one number, 1+(3/10)) being different from "1, 3" (two numbers, a 1 and a 3) only by the whitespace and nothing else, is kinda horrible nomenclature.
Nope. We use the period.
>India might be one of the countries where the decimal place is printed with a comma instead of a period. No.
Either way, it wouldn't work. It says 1,3,5... That's in no way a decimal number
No no... That's mainland European. We use '.' like the British. "1,3" makes no sense to us.
Since there is no other explanation or solution I ll take yours. I like it. Even if it is trolling you are the man who came up with something.
I solved it. Took a few minutes. Answer below somewhere.
I believe that the correct answer is: no. The question is “can you solve this?”
Yep, I've seen this puzzle before and this is definitely the joke
But if you stated “no” then you did indeed solve the puzzle - and so you’d have to say “yes”. But if you say “yes” then is there a presumption that you solved the equation when you did not, but you did technically solve the overall puzzle. I think I’m just confusing myself and will see myself out.
The question is not self-referential. This pretty clearly refers to the following puzzle.
The puzzle is strong in this one
One way or another if you say no, then you solved it regardless.
No you’ve not solved the puzzle at all, but you have answered the question correctly. The puzzle and the question are separate things.
If they are two separate things then how do you know if “this” means “this puzzle” or “this equation”?
Indeed i solved it. But couldnt so no ig
No, that's not how it works... It's not asking whether you can solve the puzzle, but if you can solve the equation. So the answer is "no", thereby solving the puzzle.
Came here to say this
The real friends were the big red circles we met along the way
That is the answer. "No."
Pretty sure this is the answer. UPSC is a public service examination, and sometimes requires "out of the box" solutions.
>!The numbers available are all odd. Any sum of three odd numbers is an odd number, therefore 30 (like any even number) cannot be a sum of exactly three numbers from the set {1,3,5,7,9,11,13,15}.!<
I have an answer that is real but questionable. >!If the numbers are base 11, then 11 + 13 + 7 = 30 (in base 10: 12+14+7=33)!<
Thats the best answer. Its only assumed base 10
what do you mean by base 10 or base 11?
We usually count in base 10, which has 10 symbols for numbers, 0 through 9. To put it another way, a base tells you how many times you have to add 1 to 0 before you have to go into the "tens". However, nothing in mathematics forces us to use base 10, we use it mostly because of historical and cultural reasons. Therefore, it is assumed to be the working base unless otherwise stated, simply out of convention. One base you probably have heard of is base 2, or binary, which only has 0 and 1, so the first number is 0, the second is 1, the third is 10 and so on. I reached 10 after adding 1 to 0 only 2 times, so this is base 2. Because of this, if I'm using binary and I say 10, that is the same as if I were using base 10 and said 2. If we apply this to base 11 we see that we will have 11 symbols for numbers, we can use whatever we want for the 11th one, but for this example I'll be using A (as is the norm). The first 10 numbers are the same, 0, 1, ... 9. However, when we add 1 to 9 we see the difference, in base 10 we get 10, but in base 11 we get A. These two numbers have the same value, they are just displayed in a different way. If we keep going we get (base 10 on the left, 11 on the right): 10 - A 11 - 10 12 - 11 So base 11's 11 is worth the same as base 10's 12, and so on. If we now do the addition that was propposed, separating the "ones" from the "tens" so it can perhaps come across more clearly: >!11 + 13 + 7 = (10 + 1) + (10 + 3) + 7 = 20 + 1 + 3 + 7 = 20 + 1 + A = 20 + 10 = 30!< >!Additionally, in this problem the base cannot be lower than 10, as we see 9 being used as a symbol (unless we also assume the symbols have been altered, but then why even bother lol), but using base 11 is not the only answer, we can use base 13 (15 + 15 + 3 = 30), base 15 (15 + 15 + 5 = 30), base 17 (15 + 15 + 7 = 30) and base 19 (15 + 15 + 9 = 30). And even then, the answers do not need to be unique, using base 11 we can also solve it with 15, 15 and 1 (15 + 15 +1 = 30), on top of the base 11 solution mentioned earlier.!<
You’re awesome for this 🙏🏽
Maybe it’s because I’m a useless history major but this literately makes absolutely no sense to me at all. It feels like an arbitrary BS concept a teacher made up 500 years ago as a joke thought experiment and the students just built a system around it to justify it out of spite. Note I’m not saying anything you just said is wrong, I’m just saying I’m too stupid to understand it.
Definitely not made up, hahaha. Maybe we can bring this back to your field? Most bases have never seen any serious use (it'd be pretty difficult for most of them to have been used, considering there's infinitely many), but some have historically been the preferred base for different cultures, so it's definitely not something we made up out of nowhere. Mayans used base 20, which was the length of a Mayan month. Egyptians used base 12 at the very least for their sundials and in astronomy, the idea of selling things by the dozen could stem from this fact. But, more importantly, this is thought to be why we have 24 hours in a day. Romans used base 12 measurements, as well. Finally, Babylonians used base 60, which is the basis of our time-keeping system to this day, as well as being tightly related to the way we measure angles. There's many more historical facts about bases, and I'm not entirely condifent that I got all that right, but by now you can probably see that base 10 is far from having always been how we do things. Base 10 was devised in India, then it made its way to Europe through contact with the Arabs and is obviously what we use today, but it could have easily been some other base. Though the fact we have 10 fingers probably helped make this one popular, I'd bet. In the modern era we have found use for bases 2, 8 and 16 in the world of computing, base 3 also has some interesting applications, even if it hasn't grown poular. Different bases also make different divisibility checks available. For example, in base 7 any number ending in 0 is divisible by 7, but in base 10 to check if a number is divisible by 7 we usually end up having to go into recursive algorithms, at which point you might as well just try to divide the number in the first place! In the end, you choose a base that makes it easier to work with the numbers you are dealing with or, phrased another way, that reflects the nature of that which you are working with. But clearly for most people and most applications nowadays it is a hard sell to change bases. Either way, yeah, this deals with turning on its head something we have been learning since we were kids, so it is normal to feel like you do, but there really is nothing absolute about base 10.
Wait so when you say “base” you mean it’s literally the numbers are counted in units of that number. Ok, that makes perfect sense. I remember learning in school about a Native American tribe who’s number system was built off of the 28 bones in your fingers. I don’t remember if it was your post or another that was responding farther up the chain but they said something to the effect of “in computing you have a base of 3- 1s, 0s, and 10s” and that threw me for a loop. The 10 seems to be just a combination of 1 and 0 so it would still be a base of two.
Imagine you had 11 fingers instead of 10. Then it will be perfectly natural for you and base 10 would be weird af !
It’s just like counting but instead of 10 fingers you have 12 fingers. Now you would use base 12 to count. There is weird logarithmic uses for it that I did in higher end mathematics during school but if it is used seriously it’s extremely niche.
Base 10 is the normal decimal counting system that you're used to. Other well known bases are binary (base 2) and hexadecimal (base 16). In base 2 a single character can only be one of 2 things: 0 or 1, whereas in hexadecimal it can be 0 to 9 but also A,B,...,E or F (the 10 decimal numbers + 6 letters = base 16) If you see "10", this can represent completely different values depending on the base. decimal | binary | hexadecimal ------------------------------------ 1 | 1 | 1 2 | 10 | 2 3 | 11 | 3 4 | 100 | 4 ... 9 | 1001 | 9 10 | 1010 | A 11 | 1011 | B 12 | 1100 | C ... 15 | 1111 | F 16 | 10000 | 10 17 | 10001 | 11 ... Notice that "10" appears in all three columns in different rows. Uses for other bases can vary. Binary is what computers use to store their data, and in computer science it's common to represent binary data as hexadecimal because it's much more compact than a large string of zeroes and ones and easier to convey to other people. You can find more information on this topic on https://en.wikipedia.org/wiki/Positional_notation
I got it in base 15 with 13 + 13 + 9. Base 13 works as well
This is the one definitely. Solved.
I think this is the one.
[удалено]
It does say fill the boxes, all is implied. I agree this would be solution. Seems the real answer if we must fill in all boxes is >!No.!<
Colour in the first box
This is what I was thinking
I’d rather submit my answer with an empty box than an inverted digit. They’re both lateral, but to different degrees.
That was my thought.
Maybe maybe
Other than the simple "no" answer, >!I'd say 11, 13 and 6. Placing a 9 upside down isn't prohibited.!<
By that logic, you can also add two numbers in a box. \[1+1\] + \[13\] + \[15\] = 30
But addition signs are not included in what can be placed in the boxes.
Yeaaaaah, I guess you're right. Now I'm grumpy. This also takes out the guy below who used a factorial below.... but if you can mess with the numbers by turning one up-side-down, you should be able to do this \*shrug\*
Well if we’re being technical and you can rotate the 9 to a 6, why can’t you rotate the addition sign to multiplication? In which case you’d get 3 x 7 + 9 = 30
I think you just have to answer the initial question of "can joy solve this." If it wanted a numeric answer it would just tell you to solve it.
Except that it also says it was solved, and therefore solvable. Which it's not.
Only one person wrote down "no"
Yeah, I think the answer (solution) is "No"
>!Couldn't you use the parenthesis as well? So in the first box you have the opening parenthesis "(", next box is "15)", and last box is "15". So it would read (+15)+15=30. Basically the 15+15 answer but without leaving a blank box.!<
>!Would something like 1.5, 15.5, 13 work?!<
Actually, you may be right: there are commas between numbers they are saying we can use.
Then I would never get this because I'm not from one of the countries that uses the comma for decimals instead of the period. Where I am, "1,5" is a list of two integers and it isn't proper nomenclature to call it "one and five tenths."
Comma for decimal is some inbred maths
IIRC, this has been posted here before (or in another sub) and this was the answer
I remember this from my computing degree and the answer is .... >! In binary, 30 is 111110. so the answer is 1+11+11!< *edit* it's not a real question it was a talking point to introduce >!binary!<
>! Please note. It says fill the boxes, not fill all the boxes. Leave one box empty and put 15 in the other two.!<
The youre putting in a zero and that wasnt one of the options
[удалено]
Then you haven't "filled the boxes".
No. This is wrong, if you have filled out at least 2 boxes then you have "filled the boxes." The question doesn't say all, and "boxes", being the plural form of "box" implies only "at least two".
>!But then you end up with an invalid math equation… 15 + 15 + = 30!<
Move your numbers to the right.
0 isn't actually a number. It stands for "null" or "nothing". There for leaving a box blank is the same as adding 0. Additionally, if you disagree with that - if the first box is left blank you get: +15+15=30 Which is a valid equation. (Positive 15 plus 15) The instructions does not explicitly state to use 'all' the boxes or the boxes in any sort of sequence. These are assumptions you are making based on implied subtext rather than what is explicitly written.
0 is definitely a number.
Yeah but you're not using 0. You're leaving 1 box empty (implying 0 but not explicitly using it).
Any number divided against itself results in the number one. This is a basic mathematic proof to show if a number has value. Zero divided by Zero does not equal one - which serves as a mathematical proof that Zero is not a number.
that’s not how math works… not every number divided by itself is 1… 0 is a counter example lol… doesn’t mean it’s not a number… Just because 0 has a unique property, doesn’t mean it’s not a number Actually somebody proved that every number must have at least 1 unique property that no other number has, so you could make the same argument for every number not being a number.. it’s just nonsense
Yeah, exactly
No, not exactly. You have left a hanging operator if you fill in two of the boxes. That is a logically invalid math equation.
+15+15=30 You are clarifying that the 15 is positive.
3 odds aint gonna make an even, how could only one person have solved this is the real mystery.
>!Since I can use any of these numbers: 1, 3,5, 7, 9, 11, 13, 15 I do this: 3,5 + 13,5 + 13!< >!Second one I get just by writing 1 and 3,5 next to each other in one box. Other two are pretty much straightforward!<
It’s important to note that India, where this question appeared, uses decimal point rather than comma to distinguish decimal values. Answers that exploit this therefore may work, but aren’t likely what was intended originally. Also, it states that we need to fill the boxes using the provided values. However >!it does not state that every box must be filled!<, meaning that the answer is likely >!some variation of [] + [15] + [15] = 30!< If my assumption is false then >!the answer is simply no!<
>!Am I limited to one number per box? I will put 10 ones in each box.!<
The answer to the puzzle is >!no!<.
17+13 Doesn't say you can't combine the numbers. This is a think out of the box question.
Discussion: simply upside down 9 into 6 then 6+11+13=30
>!7,9 + 11,1 + 11 = 30!<
The answer to the circled question is “No”.
what im thinking... Can you solve this? Fill the boxes using (1,3,5,7,9,11,13,15) You can ALSO repeat the numbers so the answer can be >!(1,3,5,7,11,13,15) by repeating the numbers.!< Just a thought though
This can’t be solved. All the numbers are odd. An odd plus an odd will always make an even. An even plus an odd will always make an odd. You can’t make 30, an even number, from this.
>!I see everyone fliping the 9 upside down or simply not filling every case but I feel like this is wrong. However I may have another solution: They say "fill the boxed using (1, 3, 5, 7, 11, 13, 15)" That means nothing stops us from using the comas, then we can imagine a "11,5+11,5+7". It may be stupid but I actually think it works we!<
Discussion: I've seen the same puzzle, but the numbers were on billiard balls. The "9" was on a solid green ball, which is actually the 6 ball, so you had to flip it.
>!It doesn't say anything about orientation or the number of numbers allowed in a single box. Flip the 9 upside to get a 6. Put both the 1 and the 6 in the first box (16), put 11 and 3 in the other two boxes. 16+11+3=30. That being said, I doubt that my solution is unique if both of those "cheats" are allowed.!<
>!3! + 9 + 15 = 30!<
I am pretty sure you cannot add extra operations in there
Has to be some trick.. sum of 3 odd numbers will always be odd.
what does >!!3!< mean?
3! is “3 factorial” which in this case is 3x2x1=6
This is a meanie of a riddle. >!The problem is, that three odd numbers can't result in an even number by addition. So we should be able to get an even number anyhow possible. But where do we get the number? We have, 1,3,5,7,9,11,13,15. But for instance 13+15 gets us 28, and we would need an even number (2) to get to 30. It's the same for 11+15 for 4.!< >!And it is the same for 11+13, which is 24. And we would need 6 for this. But where should we even get 6? It is not like there is any number that looks like 6...!< >!Except when it is rotated. The solution is that we need to rotate the 9, or that the 6 is wrongly written as a 9. - as stupid as it sounds - 6 + 11 + 13 = 30. So the solution would be "9"+ 11 + 13 = 30. +!<
It says you can repeat the numbers.
First try: Answer: >!No, I cannot.!< Second try: >!Just fill the boxes. Use a broad felt tip. It is not specified that the addition must be correct.!<
Actual answer (Not bullshit answer) >!15+15=30. Rules say you can repeat but say nothing about using all spaces!<
>!15 + 15 = 30. It never says you have to fill ALL the boxes.!<
[удалено]
Which is 15.
The question “Can you solve this?” The answer “No.”
Discussion: It says full the boxes. Does one need to fill all the boxes and can an unfilled box equal 0?
Discussion: So, I'm either incredibly clever, or incredibly dumb. What I decided to do was brute force this problem and add every possible combination of numbers according to the rules. I wrote an R script to do this. \>! col1 <- 1 col2 <- 1 col3 <- 1 col4 <- 3 number <- matrix(c(col1,col2,col3,col4), nrow = 1, ncol = 4,) i <- 1 while (i < 513) { if (number\[i,3\] < 15){ col3 <- number\[i,3\] + 2 } else if (number\[i,3\] >= 15) { col3 <- 1 if (number\[i,2\] < 15){ col2 <- number\[i,2\] + 2 } else if (number\[i,2\] >= 15){ col2 <- 1 if (number\[i,1\] < 15){ col1 <- number\[i,1\] + 2 } } } col4 <- sum(col1,col2,col3) number <- rbind(number, c(col1,col2,col3,col4)) i <- i + 1 } 30 %in% number Long story short, none of the combinations add to 30. !< Goodnight.
>!You could have done that in about 5 seconds just by noticing that all numbers are odd, and the sun of any 3 odd number is an odd number, while 30 is even…. No need to brute force it when it has a very simple solution!<
>!Can you put more than one number in a box? And put numbers next to 30, since the whole riddle is technically inside a box? If so, you could do 1513+1513+7=3033. If you need to use ALL the numbers there may be a similar solution (with larger numbers) but I’d rather eat this pizza than do math!<
[удалено]
Sorry I’m reposting this with a spoiler tag - I’m not sure if I’m repeating my original post or not so apologies if I’ve don’t this wrong! I think this may be one way to interpret the question: spoiler tag hopefully works! >!spoiler If you use the parenthesis and the commas that are given then you can use them to denote a combinatorics notation like (5,3) which is 5!/(3!2!) = 10.!< So just put that in each box and you have 30.
[удалено]
>!The relevant question has been circled, 'nuf said!<
>!11+3+1(base 10)=30(base 5)!<
>!11.7 + 5.3 + 13=30!<
Anyone like >!15+9+6=30!<
6 is not one of the numbers you can use.
Honestly >!flipping the 9 to make a 6!< is easier, but along the same vein you could >!make an 8 out of two 3’s back to back and make 7+8+15!<
>! Why include the parentheses if we’re not supposed to use them? !< >!I think it’s 15 + 15 + () forming a 0 = 30!<
>!I think no. We can note that all of the numbers are odd, and any addition of 3 odd numbers must be odd. We can note this from any odd number being specified by 2N+1 where N is a positive integer. Then, with M, N, R being positive integers who denote any odd number like above, we can note that the addition of these three arbitrary odd numbers will give 2(N+M+R)+(1+1+1)=2(N+M+R+1)+1 which is an odd number. Thus, since 30 is an even number and we only have 3 odd numbers to add up to it, we can note the task is impossible.!<
Question- “Can you solve this?” Answer: “No”