Consider selecting one card at a time from a 52-card deck. What is the probability that the first card is an ace and the second card is also an ace? Express the probability in fraction format. (Note: There are 4 aces in a deck of cards) (Show all work. Just the answer, without supporting work, will receive no credit.)

(a) Assuming the card selection is without replacement.

(b) Assuming the card selection is with replacement.