Question 1160049
p(a) finding at least 1 is 1-p(finding 0)=1-0.95^8=0.3366
That is the same for b.
They both have to find at least 1, and that is the joint probability of 0.3366^2=0.1133 rounding at end.

Sixteen accounts are checked randomly. The probability of finding at least 1 is 1-p(finding 0)=1-0.95^16=0.5599

This makes qualitative sense in that the probability of both finding at least 1 is more restrictive than just one auditor's finding at least 1.