A bowl contains twenty cherries, exactly fifteen of which have had their seeds removed. A greedy pig, Babe, comes and eats five whole cherries, picked at random, without remarking on the presence or absence of seeds. After Babe is gone, a hungry dog, Benji, comes over and eats another five whole cherries, picked at random, from the remaining fifteen.
a. What is the probability that both Babe and Benji consumed the same number of cherries with seeds?
b. Given that Benji consumed exactly two cherries with seeds, what is the probability that Babe consumed at least two cherries with seeds?