The probability that a certain make of car will need repairs in the first six months is 0.4. A dealer sells seven such cars. What is the probability that at least one of them will require repairs in the first
Six months?
A) 0.9720
B) 0.0016
C) 0.0280
D) 0.9984

Question

Quizplus · Accepted Answer

The probability that at least one car will need repairs is 1 minus the probability that none of the cars will need repairs. The probability that a car will not need repairs is 0.6. For seven cars, this is $0.6^7 = 0.02799$. Therefore, the probability that at least one will need repairs is $1 - 0.02799 = 0.9720$.

The Probability That a Certain Make of Car Will Need