I stole this from the XKCD rss feed, but figured it apropos enough to share with the group. Here it is!

-Mark

Sue and Bob take turns rolling a 6-sided die. Once either person rolls a 6, the game is over. Sue rolls first. If she doesn’t roll a 6, Bob rolls the die; if he doesn’t roll a 6, Sue rolls again. They continue taking turns until one of them rolls a 6.

Bob rolls a 6 before Sue.

What is the probability Bob rolled the 6 on his second turn?

The answer is not 5/36.


Riddle 2 Solution

THE REAL SOLUTION ***spoilers***

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