The irs has a group of 45 tax returns, 15 of which contain errors. an irs auditor randomly selects 3 tax returns from this group. what is the probability the auditor selects none of those containing errors? round to four decimal places.

Out of 45, there are 45-15=30 that do not contain errors.

If the auditor randomly selects 3 returns, without replacement, then
P(1)=30/45,
for the second one, there will be 29 correct returns out of 44, so
P(2)=29/44
Similarly,
P(3)=28/43
Therefore, by the multiplication rule, the probability of selecting 3 correct returns is the product
P(1)*P(2)*P(3)=30*29*28/(45*44*43)=406/1419

When rates are expressed as a quantity of 1, such as 2 feet per second or 5 miles per hour, they are called unit rates. if you have a multiple-unit rate such as 120 students for every 3 buses, and want to find the single-unit rate, write a ratio equal to the multiple-unit rate with 1 as the second term.