Springfield will be opening a new high school in the fall. The number of underclassmen (9th and 10th graders) must fall between 600 and 700 (inclusive), the number of upperclassmen (11th and 12th graders) must fall between 500 and 600 (inclusive), and the number of students cannot exceed 1000.Let a represent the number of underclassmen and let b represent the number of upperclassmen. Write a set of inequalities that models the constraints on the composition of the student body.