The average weight of 21 boys was recorded as 64kg. If the weight of the teacher was added, the average increased by one kg. What was the teacher's weight?
Correct Answer: 86kg
Explanation:
Here, n = 21, a = 64, b = 65
Weight of teacher = n(b - a) + b
= 21( 65 - 64) + 65
= 21 + 65
= 86 kg
