Math problem that went viral.

[leeway]

nice python script. and also good collection of the math puzzles

[rkbabang]

Edit: yes, there is a single solution that follows from the inferences of conversation between P & Q.

I wrote a Python script and got the answer. It would be somewhat hard, but possible to do it by hand.

If anyone wants spoilers the answer is also at http://www.mathpropress.com/archive/iams/vol14.ascii

Now back to wasting my workday on other non-productive endeavors like value investing 

duh,   I see where I messed up.  For some reason I was thinking M couldn't be prime, but it is S that can't be the sum of primes.
Thanks for the solution.

[matjone]

this one is relatively straight forward with this type of problems. I just spent an evening and more to solve a similar but much more complicated problem:
2 numbers a and b, a >=b, both integers between 2 and 99. Mr. P knows the sum S=a+b, and Mr. Q knows the product M=a*b. Here is the conversation:
Q: I don't know what are a and b.
P: I know you don't know, and I don't know either.
Q: I know now.
P: I also know now.

What are a and b?

are we supposed to be able to do this in our head?

when p said "i know you don't know" I am guessing that meant he knew q didn't know it before q said anything, right?

[Jurgis]

this one is relatively straight forward with this type of problems. I just spent an evening and more to solve a similar but much more complicated problem:
2 numbers a and b, a >=b, both integers between 2 and 99. Mr. P knows the sum S=a+b, and Mr. Q knows the product M=a*b. Here is the conversation:
Q: I don't know what are a and b.
P: I know you don't know, and I don't know either.
Q: I know now.
P: I also know now.

What are a and b?

are we supposed to be able to do this in our head?

when p said "i know you don't know" I am guessing that meant he knew q didn't know it before q said anything, right?

If you can do it in your head, you're pretty genius level.
I'd suggest pen and paper at least, programming makes this easier though. I got almost to the end with pen and paper, but programming script makes last step easier to verify and doublecheck.

The answer to your second question is "yes".

[matjone]

i am not a programmer.  I was trying to do it with excel but I am not sure it is up to the task

Does the order matter? If it is 6 then you know your numbers are 2 and 3, but you don't know whether it's a=2, b=3, or the other way around.

[Jurgis]

i am not a programmer.  I was trying to do it with excel but I am not sure it is up to the task

Does the order matter? If it is 6 then you know your numbers are 2 and 3, but you don't know whether it's a=2, b=3, or the other way around.

From the problem:

2 numbers a and b, a >=b,

Good luck

[Lowlight]

Am I the only one who doesn't see the answer in the link?  I would like to check what I came up with.  Someone message me the answer?  Or should I simply post my guess?

[Pretium]

Am I the only one who doesn't see the answer in the link?  I would like to check what I came up with.  Someone message me the answer?  Or should I simply post my guess?

http://mashable.com/2015/04/13/math-is-hard/