there are 4 aces in a deck of 52 cards
probability of 1st card being an ace = 4/52
without replacement
probability of 2nd card being an ace = 3/51
without replacement
probability of 3rd card being an ace = 2/50
without replacement
probability of 4th card being an ace = 1/49
probability of all 4 cards being aces : 4/52 * 3/51 * 2/50 * 1/49 =
24/6,497,400 reduces 1/270,725
