Two cards are randomly chosen without replacement from an ordinary deck of 52 cards. Let B be

Question:

Two cards are randomly chosen without replacement from an ordinary deck of 52 cards. Let B be the event that both cards are aces, let As be the event that the ace of spades is chosen, and let A be the event that at least one ace is chosen. Find
(a) P(B|As)
(b) P(B|A)