CAPE Pure Mathematics Unit 2 · May/June 2006 · Paper 2 · Question 5(b)(ii)

In an experiment, p is the probability of success and q is the probability of failure in a single trial. For n trials, the probability of x successes and (n - x) failures is represented by ^n C_x p^x q^(n-x), n > 0. The probability that John will hit the target at a firing practice is 5/6. He fires 9 shots.

Calculate the probability that he will hit the target NO MORE than seven times.