(a): there is a 8/10 probability of pulling a 3 and a 2/10 probability of pulling a 5 so the expected value is 810(3)+210(5) Expected value for drawing one slip of paper, this is equal to 3.4 or 34/10 or 17/5
(b): well, this would be the exact same idea except the probabilities are different, now the expected value is 911(3)+211(5) which simplifies to 37/11
(c): Once again, same idea, the expected value would be 1012(3)+212(5) which simplifies to 10/3
If you have any questions, just ask :)