If three random integers are independently chosen from 1 to n, what is the probability that the first two sum to the third?
Source: Quora
(In reply to
re: solution: as presented and with a complication by Steve Herman)
Yes, as I thought about it later, I recognized that that way of looking at it works. I was making it more complicated than necessary. Oh, well, at least looking at it a different way is an independent verification the formula is correct.

Posted by Charlie
on 20150515 13:56:06 