Question

If a certain medicine cures 90% of the people who take it, what is the probability that if 9 people take the medicine that 6 will be cured?

A) 0.01
B) 0.02
C) 0.04
D) 0.33

Answer 1

option C (0.04) is the correct answer

Answer 2

This is an example of binomial distribution probability. The probability that a person gets cured by the medicine (p) is 90% or 0.9. The probability that a person does not get cured by the medicine (q) is 100 - 90 = 10% = 0.1. The probability of a binomial distribution is given by nCx (p)^x (q)^(n - x); where n is the sample size, x is the number of success, p is the probability of success, and q is the probability of failure. Therefore, the probability that out of 9 people that takes the medicine, 6 will be cured is given by 9C6 (0.9)^6 (0.1)^3 = 84 x 0.531441 x 0.001 = 0.0446. Therefore, option C (0.04) is the correct answer.