Probability Question 20

Question: A man draws a card from a pack of 52 playing cards, replaces it and shuffles the pack. He continues this processes until he gets a card of spade. The probability that he will fail the first two times is

[MNR 1980]

Options:

A) $ \frac{9}{16} $

B) $ \frac{1}{16} $

C) $ \frac{9}{64} $

D) None of these

Show Answer

Answer:

Correct Answer: C

Solution:

The required probability is given by $ \frac{{}^{39}C_1}{{}^{52}C_1}\times \frac{{}^{39}C_1}{{}^{52}C_1}\times \frac{{}^{13}C_1}{{}^{52}C_1}=\frac{3}{4}\times \frac{3}{4}\times \frac{1}{4}=\frac{9}{64}. $