Arithmetic Ability
 Probability

106 / 132

Q.

A bag contains 2 red, 3 green and 2 blue balls. Two balls are drawn at random. What is the probability that none of the balls drawn is blue?

View Answer

Correct choice: A

Explanation:

Total number of balls = (2 + 3 + 2) = 7. Let S be the sample space. Then, n(S) = Number of ways of drawing 2 balls out of 7 =7C2 = 21 Let E = Event of drawing 2 balls, none of which is blue. n(E) = Number of ways of drawing 2 balls out of (2 + 3) balls =5C2 = 10 Therefore, P(E) = n(E)/n(S) = 10/ 21.
106 / 132