Question

In the game of blackjack, the player automatically wins if his two cards add up to 21 points. If you assume an Ace is worth 11 points, and the Jacks, Queens, Kings, as well as 10's are all worth 10 points; what is the probability that you get a 21 when you are dealt 2 cards?

Answer 1

so you need one of the four aces --- C(4,1) = 4
plus one of the remaining 16 "ten" point cards
= C(16,1)

so prob of gettting 21 when dealt 2 cards
= C(4,1)xC(16,1)/C(52,2)
= 64/1326
= 32/663 or appr .048