The average weight of 5 boys is increased by 9 kg when one of them, whose weight is 39 kg, is replaced by another boy. What is the weight (in kg) of the new boy?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is Option 4 i.e. 84.
Increase in average = 9 kg
Number of boys = 5
Total increase in weight = 5 × 9 = 45
Old boy’s weight = 39 kg
New boy’s weight = 39 + 45 = 84 kg