Question

The mean weight of 21 students is 21 kg. If a student weighing 21 kg is removed from the group, then what is the mean weight of the remaining students ?
A. 20 kg
B. 21 kg
C. 19 kg
D. 22 kg

Answer 1

Correct Answer - B
Given that the mean weight of 21 students `=21` kg.
`:.` The total weight of 21 students `=21` (21 kg)
If a student weighing 21 kg is removed from the group, then the total weight of 20 students `=21` (21 kg) 21 kg.
`:.` The mean weight of 20 students `=420/20=21` kg
Hence, the correct option is (b).