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 ?

Answer: Option D

Let the weight of 1 student = x kg
The weight to 15 student = 15x kg
Let the weight of new comer = y kg
∴ According to the question,
⇒ 15x - 40 + y = 15 (x + 1.5)
⇒ 15x - 40 + y = 15x + 22.5
⇒ y = 62.5 kg