A tennis player makes a successful first serve 51% of the time. If she serves 9 times, what is the probability that she gets exactly 3 successful first serves in? Assume that each serve is independent of the others.
A) 0.154
B) 0.00184
C) 0.133
D) 0.0635

Question

A tennis player makes a successful first serve  51%  of the time. If she serves 9 times, what is the probability that she gets exactly 3 successful first serves in? Assume that each serve is independent of the others.
A)  0.154 
B)  0.00184 
C)  0.133 
D)  0.0635

Quizplus · Accepted Answer

This is a binomial probability problem where the number of trials n = 9, the number of successes k = 3, and the probability of success on a single trial p = 0.51. The probability of exactly k successes in n trials is given by the formula P(X = k) = (n choose k) * p^k * (1-p)^(n-k). Plugging in the values, we get P(X = 3) ≈ 0.154.

A Tennis Player Makes a Successful First Serve 51