Company X shipped 5 computer chips, 1 of which was defective and company Y…
2007
Company X shipped 5 computer chips, 1 of which was defective and company Y shipped 4 computer chips, 2 of which were defective. One computer chip is to be chosen uniformly at a random from the 9 chips shipped by the companies. If the chosen chip is found to be defective, what is the probability that the chip came from the company Y?
- A.
2/9
- B.
4/9
- C.
2/3
- D.
1/2
Attempted by 28 students.
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Correct answer: C
First, calculate the total number of defective chips. Company X shipped 1 defective chip and Company Y shipped 2 defective chips, resulting in a total of 3 defective chips. Since the chosen chip is known to be defective, we restrict our sample space to these 3 chips. Among the 3 defective chips, 2 originated from Company Y. Thus, the conditional probability that the chip came from Company Y is the number of defective chips from Y divided by the total number of defective chips, which equals 2/3.