Question

the mean weight of 21 students of a class is 52kg. If the mean weight of the first 11 students of the class is 50kg and that of the last 11 students is 54kg, find the weight of 11th student

Answer 1

Given, mean weight of 21 students of the class = 52kg
Total weight = 52*21 = 1092kg
Weight of first 11 students = 50*11 = 550kg
Weight of last 11 students = 54*11 = 594kg
Weight of 11th person = 550+594-1092 = 1144-1092 = 52kg
[∵ The weight of the 11th person is added twice, the remainder will give us the weight of the 11th person]
Hope this helped.

Answer 2

hope you get.......