Many high school students the Scholastic Aptitude Test (SAT). Beginning in March 2005, students taking the SAT received three scores: a critical reading score, a mathematics score, and a writing score. The average total of 2007 high school seniors who took the SAT was 1511. The average mathematics score exceeded the reading score by 13 points and the average writing score was 8 points less than the reading score. What was the average score for each category?

This problem is system of three equations… I just can’t figure out how to set up! please help.. thanks

M = Math score

R = Reading Score

W = Writing Score

(M+R+W)/3 = 1511

M = R+13

W = R-8

There are the 3 equations, solve away….