Assume that 2 cards are drawn in succession and without replacement from a standard deck of 52 cards. Find the probability that the following occurs: the second card is a 9, given that the first card was a 9.

Answer 1

Use the definition of conditional probability:
P(X9|9X) in the previous question.
P(X9∩9X)/P(9X)
=P(99)/P(9x)
=(4/52)*(3/51) / (4/52)
=3/51