An automobile plant contracted to buy shock absorbers from two suppliers X and…
2012
An automobile plant contracted to buy shock absorbers from two suppliers X and Y. X supplies 60% and Y supplies 40% of the shock absorbers. All shock absorbers are subjected to a quality test. The ones that pass the quality test are considered reliable. Of X’s shock absorbers, 96% are reliable. Of Y’s shock absorbers, 72% are reliable.
The probability that a randomly chosen shock absorber, which is found to be reliable, is made by Y is
- A.
0.288
- B.
0.334
- C.
0.667
- D.
0.720
Attempted by 42 students.
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Correct answer: B
Probability that the absorber is reliable = 0.96*0.6 + 0.72*0.4
= 0.576 + 0.288
Probability that the absorber is from y and reliable =
(Probability that is made by Y) X (Probability that it is reliable)
= 0.4 * 0.72
= 0.288
The probability that randomly picked reliable absorber is from y =
(Probability that the absorber is from y and reliable) / (>Probability that the absorber is reliable )
= (0.288)/ (0.576 + 0.288)
= 0.334