A pupil’s marks were wrongly entered as 83 instead of 63. Due to that the average marks for the class got increased by half. The number of pupils in the class is-

Answer: Option C

Let there be x pupils in the class
Total increase in marks
= x × $$\frac{1}{2}$$
= $$\frac{x}{2}$$
∴ $$\frac{x}{2}$$ = (83 - 63)
⇒ $$\frac{x}{2}$$ = 20
⇒ x = 40