Q12 of 54 Page 320

A lot consists of 144 ball pens of which 20 are defective and the others are good. The shopkeeper draws one pen at random and gives it to Sudha. What is the probability that

She will buy it?

Given,

⇒ Lot consists of total 144 ball pens.


⇒ Defective pens = 20


⇒ Non – defective pens = 144 – 20


⇒ Non – defective pens = 124


⇒ Sudha will buy pens if pen is good.


⇒ Probability that Sudha will buy pens –


⇒ P(Sudha will buy pen) =


⇒ P(Sudha will buy pen) =


⇒ P(Sudha will buy pen) =


∴ Probability of Sudha will buy a pen will .


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