To find the fraction of the class that did not receive an A, we can subtract the number of students who received an A from the total number of students and then express it as a fraction.
Number of students who did not receive an A = Total number of students - Number of students who received an A
Number of students who did not receive an A = 80 - 25 = 55
So, the fraction of the class that did not receive an A is 55/80. This fraction can be reduced to lowest terms by dividing both the numerator and denominator by their greatest common divisor, which is 5.
55 ÷ 5 = 11
80 ÷ 5 = 16
So, the fraction in lowest terms is 11/16. Therefore, 11/16 of the class did not receive an A.