Question

From past records it is known that 10% of items from a production

line are defective. If two items are selected at random, what is the
probability that only one is defective?

Answer 1

Answer: 0.18

Explanation:

P(1 unit is defective)= C2 1* P^1*Q^1

C2 1= 2!/(1!*(2-1)!)=2

P=0.1 - probability that items from a production line are defective

Q=1-0.1=0.9 - probability that items from a production line are functional.

P(1 unit is defective)= 2*0.1*0.9=0.18