Bunuel
Katie, Ace, and Rory interviewed for jobs at companies A, B, and C, respectively. The probability that Katie will get a job offer from company A is 1/4 ; the probability that Ace will get a job offer from company B is 1/2; and the probability that Rory will get a job offer from company C is 5/8 . The three companies have no connections to one another, so the job offers are mutually independent. What is the probability that Katie and Ace will get job offers, but not Rory?
(A) 3/64
(B) 5/64
(C) 18
(D) 3/8
(E) 9/8
As this is a very long word question, we'll first write down what we're told as expressions so we don't get confused.
This is a Precise approach.
Katie, company A: p = 1/4
Ace, company B: p = 1/2
Rory, company C: p = 5/8
question: Katie and Ace get job offer, Rory doesn't.
Now that everything is nice and organized, it should be clear that our calculation is 1/4 * 1/2 * (1 - 5/8) = 1/8 * 3/8 = 3/64.
(A) is our answer.