Question

The average weight of 15 students in a class increases by 1.5 kg when one of the students weighing 40 kg is replaced by a new student. What is
the weight (in kg) of the new student?
1. 64.5 kg
2. 60 kg
3. 56 kg
4. 62.5 kg

Answer 1

Correct Answer - Option 4 : 62.5 kg

Given:

The average weight of 15 students in a class increases by 1.5 kg 

40 kg is replaced by a new student

Calculation:

Let the average weight of each student be x

Total weight of students initially = 15 × x

New weight of total students = 15 × (x + 1.5)

15 × (x + 1.5) = 15 × x - 40 + weight of new student

Weight of new student = 15 × 1.5 + 40 = 62.5 kg

∴ Weight of new student  is 62.5 kg.