Question

12 defective pens are accidentally mixed up with 132 good ones. It is not possible to just look at a pen and tell whether it is defective or not. One pen is taken out at random from the lot. Find the probability that the pen taken out is defective.

Answer 1

Given: 12 defective pens and 132 good pens (total 144).

Total possible outcomes = 144.

Number of favourable outcomes (defective) = 12.

Probability = `"Favourable"/"Total"`

= `12/144`

= `1/12 ≈ 0.08333`

The probability that the pen taken out is defective = `1/12`.