Question

Among 10 laptop computers 5 are good and 5 are defective. Unaware of this, a customer buys 6 laptops. Given that at least 2 purchased laptops are defective, what is the probability that exactly two are defective?

a) 1/2
b) 1/5
c) 5/10
d) None of the above

Answer 1

The probability of exactly two defective laptops out of six can be found using combinations. The correct answer is that the probability is 1/14.

Step-by-step explanation:

To find the probability that exactly two out of six laptops are defective, we need to use the concept of combinations. There are C(6,2) = 15 possible ways to choose two defective laptops out of six. Similarly, there are C(4,4) = 1 possible ways to choose four good laptops out of four.

Therefore, the probability of exactly two defective laptops is given by:

P(exactly two defective) = (C(6,2) * C(4,4)) / (C(10,6)) = (15 * 1) / 210 = 1/14

So, the correct answer is d) None of the above.