Question 1060894
There are {{{57-8=49}}} returns with no errors.
There are {{{57*56*55/(1*2*3)}}} possible sets of 3 returns that the auditor could pick.
Of those {{{49*48*47/(1*2*3)}}} are sets of 3 returns with no errors.
The number of possible sets of 3 returns with no errors,
as a fraction of the number of possible sets of 3 returns available for auditing is
{{{49*48*47/(57*56*55)=about 0.630}}} ,
so the  probability that the auditor selects none of the return containing errors is about {{{highlight(0.630="63.0"/100="63.0%")}}} .