The average marks of boys in a class is 70, and for girls, it's 75. If there are 20 girls and 30 boys, what is the average marks of the whole class?
Show answer & explanation
Correct answer: D
Explanation
Total marks of boys = 30 × 70 = 2100
Total marks of girls = 20 × 75 = 1500
Total marks = 2100 + 1500 = 3600
Total students = 30 + 20 = 50
Overall average marks = 3600/50 = 72