Question

A company manufactures scooters at two plants, A and B. Plant A produces 80% and plant B produces 20% of the total product. 85% of the scooters produced at plant A and 65% of the scooters produced at plant B are of standard quality. A scooter produced by the company is selected at random and it is found to be of standard quality. What is the probability that it was manufactured at plant A?

Answer 1

Consider S as the standard quality

Here we should determine

P (A/S) – probability that selected standard scooter is from plant A

We know that

Probability that scooter is from A

P (A) = 80/100

Probability that scooter is from B

P (B) = 20/100

Probability that standard scooter from A

P (S/A) = 85/100

Probability that standard scooter from B

P (S/B) = 65/100

So we get

On further calculation

= 68/81

Hence, the probability of selected standard scooter is from plant A is 68/81.