Question 1047570
average=total/n, n=3, average desired is 70
3*70=210, and that must be the minimum for the total.
210-(52+64) on first two tests is 94.
He needs a 94.
Also,
the first test was 18 below the mean, and the second was 6 below.  The third test must be (18+6=24) above the mean or 94.