Posted by Maria on .
You pick two cards from a deck of 52 cards. Find the probability that the first card was a spade given that the second card was a spade.

Math 
PsyDAG,
The probability of both/all events occurring is determined by multiplying the probabilities of the individual events.
Assuming no replacement:
first spade = 13/52
second spade = 12/51
With replacement:
Second spade = 13/52