Question

the average marks of three sections of a class were 60,74 and 80 respectively.if the number of students in these sections were 40,50 and 60 respectively,find the average marks of the whole class

Answer 1

Let consider the sec. A B &C

A=60*40=2400

B=74*50= 3700

C=80*60= 4800

2400+3700+4800= 10900/150= 72.66

Answer 2

Let us consider the sections are P, Q, R

In section P number of students is 40, and average marks is 60

∴ P=60×40=2400

In section Q number of students is 50, and average marks is 74

∴Q=74×50= 3700

In section R number of students is 80, and average marks is60

∴ R=80×60= 4800

∴ The average marks of the whole class :-

2400+3700+4800= 10900/150= 72.66

Ans :-The average marks of the whole class is 72.66