Two classes took the same test. One class of 20 students made an average grade of 85%, the other class of 30 students made an average grade of 70%. The average grade for all students across both classes is:
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 76%.
Class 1: 20 students, average = 85% → total = 20 × 85 = 1700
Class 2: 30 students, average = 70% → total = 30 × 70 = 2100
Total students = 20 + 30 = 50
Total marks = 1700 + 2100 = 3800
Average grade = 3800 ÷ 50 = 76%