Judging from recent experience 5 percent of the computer key

Judging from recent experience, 5 percent of the computer keyboards produced by an automatic, high-speed machine are defective. If six keyboards are randomly selected, what is the probability that none of the keyboards is defective?

Solution

P(not defective) = 1 - 0.05 = 0.95

Thus,

P(none are defective) = 0.95^6 = 0.735091891 [ANSWER]