Question

A sample of 3 different calculators is randomly selected

from a group containing 13 that are defective and 15 that
have no defects. Assume that the sample is taken with
replacement. What is the probability that at least one of
the calculators is defective? Express your answer as a
percentage rounded to the nearest hundredth without
the % sign.

Answer 1

10.01

Explanation:

13 defective and 15 non defective calculators mean the total amount of calculators is 28

So there is a 13/28 chance that if we pull one calculator out, it will be defective

Since 3 calculators are pulled out, we cube 13/28

= (13/28)*(13/28)*(13/28)

= 2197/21952

=0.10008199708

as a percentage this is 10.008199708%

rounded -> 10.01