The probability that patient recovers from a delicate heart operation is 0.9. What is the probability that exactly 5 of the next 7 patients having this operation survive?

Answer 1

C(7,5)(.9)^5(.1)^2
= .124

Answer 2

The survival rate during a risky operation for patients with no other hope of survival is 74%. What is the probability that exactly four of the next five patients survive this operation? (Give your answer correct to three decimal places.)