In a class of 50 students, 60% are boys. The average of marks of the boys is 62, and that of the girls is 68. What is the average marks of the whole class?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 64.4.
Given
Total students = 50
Boys = 60%
The average of the girl’s marks is 68 and the boys are 62
Number of boys in class = 50 × 60/100 = 30
Number of girls in class = 50 – 30 = 20
Average marks of girls = 68
Sum of marks of girls = 68 × 20 = 1360
Average marks of boys = 62
Sum of marks of boys = 62 × 30 = 1860
The total sum of marks of all classes = 1360+ 1860= 3220
Average marks of the whole class = 3220/50 = 64.4