Question 470576
{{{(x + (x+6) + ((x+6) + 6))/3 = 88}}}

<==> {{{(3x + 18)/3 = 88}}}
<==> x + 6 = 88 ==> x = 82, the score in the 1st exam
x + 6 = 88, the score in the 2nd exam, and 

(x+6)+6 = 94, the score in the 3rd exam.