Question

A factory produces cricket balls. The probability that the manufactured ball is defective is 0.05. Then, the probability of the ball being perfect will be:

• A. 0.95
• B. 1.05
• C. 1

Answer 1

The correct option is A 0.95

The balls manufactured in the factory can either be defective or perfect. Thus, these are complementary events.

The probability that the selected ball is defective, P(E) = 0.05
Let, P(E') be the probability that the selected ball is perfect.
In case of complementary events,
P(E) + P(E’) = 1
$\Rightarrow 0.05+P\left(E^{\prime }\right)=1$
$\Rightarrow P\left(E^{\prime }\right)=0.95$
Thus probability of the ball being perfect = 0.95.