Find the indicated probability. Express answers as decimals.
-An IRS auditor randomly selects 3 tax returns from 57 returns of which 15 contain errors. What is the probability that she selects none of those containing errors?
A)0.0156
B)0.4001
C)0.3923
D)0.0182

Question

Quizplus · Accepted Answer

The probability of selecting none of the returns containing errors can be calculated using combinations. The total number of ways to select 3 returns out of 57 is 57C3. The number of ways to select 3 returns that do not contain errors (from the 42 that don't contain errors) is 42C3. The probability is therefore (42C3) / (57C3) = 0.3923.

Find the Indicated Probability. Express Answers as Decimals