Q10 of 11 Page 215

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

The no. of Good Pens = 132


The no. of total Pens = Defective Pens + Good Pens


⇒ The no. of total pens = 132 + 12


= 144


Probability (Pen taken out is Good one)


=


=


=


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