Question

There are two sections $A$ and $B$ of a class consisting of $36$ and $44$ students respectively. If the average weight of section $A$ is $40$ kg and that of section $B$ is $35$ kg, find the average weight of the whole class?

Answer 1

Total weight of $80(36+44)$ students

$=36\times 40+44\times 35$kg

$=1440+1540=2980$ kg.

$\therefore$ weight of the total class$=\frac{2980}{80}$kg $=37.25$ kg