Question 1114367
Assume that X is the maximum possible score you can get on the test,
{{{(A+B)/2=(70/100)X}}}
{{{A+B=0.7X}}}
and also you know the sum of their scores,
{{{A+B=84}}}
So substituting,
{{{84=0.7X}}}
{{{X=84/0.7}}}
{{{X=120}}}