The average weight of 20 students in a class is increased by 0.75 kg when one student of 35 kg replaced by a new student. Weight of the new student (in kg) is :

Answer: Option D

Let the weight of the new student = x kg
According to the question,
$$\frac{x-35}{20}$$ = 0.75
⇒ x - 35 = 15
⇒ x = 50