The answer to C would be 3/4 of the P for blue/green. So, if you have 24 marbles, and 1/3 of them are blue OR green, then that means 8 of them could be blue or green.

If P for green is 1/4, then 3/4 of of that bag is either blue or yellow. So the answer to 2 is wrong.

ok so if P out of 24 for green is 1/4 that means there are 6 green marbles, so

THERE ARE ONLY 2 BLUE MARBLES

OK GOT IT

#3 is 2 blue marbles, which means #2 would be 1/12 probability