A monkey likes eating olives and in a plate there are twenty olives and exactly fifteen of

which have had their seeds removed. The monkey is being greedy and after picking randomly she eats

five whole olives without noticing the presence of seeds. Later, an olive is randomly picked from the

remaining fifteen olives.

a)

What is the probability that the olive has seed in it?

b)

What is the probability that the monkey ate up at least one seed given the olive contains a seed?