Q14 of 105 Page 576

In a box containing 100 bulbs, 10 are defective. The probability that out of a sample of 5 bulbs, none is defective is

In this question, let us assume X represent the number of times selecting defected bulbs in a random sample of given 5 bulbs


Also, the repeated selection of defective bulbs from a box are the Bernoulli trials


Clearly, we have X has the binomial distribution where n = 5 and


And,




∴



Hence, probability that none bulb is defective = P (X = 0)





∴ option C is correct

More from this chapter

All 105 →
12

Find the probability of throwing at most 2 sixes in 6 throws of a single die.

 13

It is known that 10% of certain articles manufactured are defective. What is the probability that in a random sample of 12 such articles, 9 are defective?

 15

The probability that a student is not a swimmer is 1/5. Then the probability that out of five students, four are swimmers is

 1

A and B are two events such that P (A) ≠ 0. Find P(B|A), if:

(i) A is a subset of B


(ii) A ∩ B = φ