Question 1037987
So the average was,
{{{A=(90+X+Y)/3=83}}}
and 
{{{X=Y-3}}}
Substituting,
{{{(90+Y-3+Y)/3=83}}}
{{{87+2Y=249}}}
{{{2Y=162}}}
{{{Y=81}}}
So then,
{{{X=81-3}}}
{{{X=78}}}
So her test scores are 90,78, and 81.