Originally Posted by

**wallace** Ok

Question 1

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A factory has two production lines for microwave ovens, A and B. The probability that a microwave oven from line A will prove to be faulty when checked is 0.008. The probability that a microwave oven from line B will prove to be faulty is 0.012. Line A produces three times as many microwave ovens as line B.

(i)

Find the probability that a randomly selected microwave oven will prove to be faulty.

Probability A or B to be faulty = 0.008 x 0.012

Probability A or B to be faulty = 0.0096

My doubt!

Do I need to consider that Line A produces 3 times more than B??? Even knowing that the probability is 0.008 for the total production??

(ii)

If a microwave oven is found to be faulty, find the probability that it was produced on line A.

Here i did -

P(not B) = P(A) or P(B) / P(B) = 0.00096 x 0.012 = 0.08