A game requires you to shoot basketballs with the balls landing in either of the 3 baskets labelled A,B and C. Your ball lands in A with the probability of 1/2, and you get paid $1. It lands in B with the probability of 1/4, and you get paid $2, and it lands in C with the probability of 1/4, and you get paid $0. Assuming that you are given 50 balls to shoot for free, what is the probability that you will earn at least $30?