Answer: the number if seventh grade students is 375
Step-by-step explanation:
Let x represent the number of seventh grade students are there.
Eight less than two-fifths of the seventh grade students had a perfect attendance in the first quarter. This means that the number of students that had a perfect attendance in the first quarter is
2x/5 - 8
If 142 students had perfect attendance, it means that
2x/5 - 8 = 142
2x/5 = 142 + 8 = 150
2x = 150 × 5 = 750
x = 750/2
x = 375