Question

The probability that a certain make of car will need repairs in the first four months is 0.8. A dealer sells six such cars. What is the probability that at least one of them will require repairs in the first four months? Round your final answer to four decimal places.

Answer 1

0.9999

Explanation:

One way to calculate the probability that at least one of them need repairs is that we can calculate the opposite (none need repairs) and subtract that from 1 (100%).

The probability that a car does not need repairs is 0.2. To find the probability that six cars all fulfill this 0.2 probability, we can get
`0.2^(6) =0.000064` . This is the probability that none require repairs. The opposite of this is that at least one needs repairs, so 1-0.000064 - 0.999936. Rounded to 4 decimal places, the probability is 0.9999