Exactly correct. Your comment should be at the top of this discussion. It took me forever to figure the above out when I first ran into this puzzle in 7th grade

Exactly correct. Your comment should be at the top of this discussion. It took me forever to figure the above out when I first ran into this puzzle in 7th grade. And although this problem is often used to show that humans are bad at doing probability in their heads, note how simple it is to do the probability calculation for the two scenarios that you've mentioned. What's actually hard for humans is describing models or simulations, not doing the probability. Once you explained the possibilities for original problem in a more detailed way, the answer(s) becomes obvious.