Suppose that research has shown that the probability that a missile penetrates enemy defenses and reaches its target is 0.1. Find the smallest number of identical missiles that are necessary in order to be 90% certain of hitting the target at least once.
A) 27
B) 22
C) 20
D) 21
E) 19

Question

Suppose that research has shown that the probability that a missile penetrates enemy defenses and reaches its target is 0.1. Find the smallest number of identical missiles that are necessary in order to be 90% certain of hitting the target at least once. ​
A) 27
B) 22
C) 20
D) 21
E) 19

Quizplus · Accepted Answer

To be 90% certain of hitting the target at least once, we need to find the smallest number of missiles, n, such that 1 - (0.9)^n ≥ 0.9. Solving this inequality gives n = 22.

Suppose That Research Has Shown That the Probability That a Missile