Q29 of 98 Page 686

A lot of 20 bulbs contain 4 defective ones. One bulb is drawn at random from a lot. What is the probability that this bulb is defective?

Total numbers of elementary events are: 20

Let E be the event of drawing defective bulb


The number of defective bulbs in a lot = 4


Then, the favourable outcome =4


∴ P (defective bulb) = P (E) = 4/20 = 1/5


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