Answer:
3 students
Explanation:
Mrs. Grape has 90 students. On her last test, 3/10 of these students earned an A.
Hence, the number of students that had an A = 3/10 × 90
= 3 × 9 = 27 students
Of those students, 1/9 got a perfect score.
This means of the 27 students, 1/9 had a perfect score.
This means:
1/9 of 27 students = 1/9 × 27
= 3 students
How many students got a perfect score?
Hence, 3 students got a perfect score.