Probability Question 130

Question: Fifteen persons among whom are A and B, sit down at random at a round table. The probability that there are 4 persons between A and B, is

Options:

A) $ \frac{1}{3} $

B) $ \frac{2}{3} $

C) $ \frac{2}{7} $

D) $ \frac{1}{7} $

Show Answer

Answer:

Correct Answer: D

Solution:

Let $ A $ occupy any seat at the round table.

Then there are 14 seats available for $ B. $ If there are to be four persons between $ A $ and $ B. $

Then $ B $ has only two ways to sit.

Hence required probability $ =\frac{2}{14}=\frac{1}{7}. $