A bag contains 24 balls of which x are red, 2x are white and 3x are blue. A ball is selected at random. What is the probability that it is
(i) not red?
(ii) white
Given that, A bag contains total number of balls = 24
A bag contains number of red balls = x
A bag contains number of white balls = 2x
and a bag contains number of blue balls = 3x
By condition, x + 2x + 3x = 24
⇒ 6x = 24
⇒ x = 4
∴ Number of red balls = x = 4
Number of white balls = 2x = 2×4 = 8
and number of blue balls = 3x = 3×4 = 12
So, total number of outcomes for a ball is selected at random in a bag contains 24 balls.
⇒ n(S) = 24
(i) Let E1 = Event of selecting a ball which is not red i.e., can be white or blue.
∴ n(E1) =Number of white balls + Number of blue balls
⇒ ∴ n(E1) = 8 + 12 = 20
(ii) Let E2 Event of selecting a ball which is white
Number of white ball = 8
So, required probability