Krishna
0

Step 1: Make use of the given information

NOTE:      Defective pens = 12

Good pens  = 132

Total number of pens = 12 + 132 = 144

So,  number of possible outcomes = 144

Step 2: Find the probability that pen taken out is a good one

Number of good pens = 132

So, favourable outcomes = 132

The probability of getting a good pen  =   \frac{\text{Favourable outcomes}}{\text{total number of outcomes}}

=  \frac{132}{144}

=  \frac{11}{12}