Quote Originally Posted by thenonsequitur
Okay, I figured out #2:

It's a deceivingly simple answer, but I think it's correct. Take any x coins from the pile of 50 and put them into pile A. Put all the other coins into pile B. Flip over each coin in pile A. Now you have two piles where the number of heads-up coins is the same.

I tried it for a number of cases, and it seemed to work for all of them.
Very nice