Question

Four microprocessors are randomly selected from a lot of 100

microprocessors among which 10 are defective. Find the proba
ability of obtaining at most one defective microprocessor.​

Answer 1

Explanation:

From the set of 100 with 10 defective microprocessors, the probability of picking a defective one is;

10/100 = 1/10

From the set of 99 remaining and 9 defective microprocessors, the probability of picking a defective one is;

9/99 = 1/11

From the set of 98 remaining and 8 defective microprocessors, the probability of picking a defective one is;

8/98 = 4/49

From the set of 97 remaining and 7 defective microprocessors, the probability of picking a defective one is;

7/97

Adding all 4 probabilities together, we get;

1/10 + 1/11 + 4/49 + 7/97 = 0.345 or 34.5%