Question

A blackjack is a 10-point card and an ace for a value of 21. Use your answers to parts (a), (b), and (c) to determine the probability that a player is dealt blackjack. (Hint: Part (d) is not a hypergeometric problem. Develop your own logical relationship as to how the hypergeometric probabilities from parts (a), (b), and (c) can be combined to answer this question.)

Answer 1

Results:

0.1432

0.0045

0.0905

0.0483

Explanation:

Step a:

P(A or 10, A or 10) = 20/52 * 19/51 = 5/13 / 19/51 = 95/663 = 0.1432

Step b:

P(A A) = 4/52 * 3/51 = 1/13 * 1/17 = 1/221 = 0.0045

Step c:

P(10 10) = 16/52 * 15/51 = 4/13 * 5/17 = 20/221 = 0.0905

Step d:

P(A 10 or 10 A) = 2 * 4/52 * 16/51 = 2/13 * 16/51 = 32/663 = 0.0483

As well we get the probability by subtracting a, b and c:

P(blackjack): 0.1432 - 0.0905 - 0.0045 = 0.0482