a) How many cards must be chosen from a standard deck of 52 cards to guarantee that

Question:

a) How many cards must be chosen from a standard deck of 52 cards to guarantee that at least two of the four aces are chosen?
b) How many cards must be chosen from a standard deck of 52 cards to guarantee that at least two of the four aces and at least two of the 13 kinds are chosen?
c) How many cards must be chosen from a standard deck of 52 cards to guarantee that there are at least two cards of the same kind?
d) How many cards must be chosen from a standard deck of 52 cards to guarantee that there are at least two cards of each of two different kinds?