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

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

Explanation

Let there be x pupils in the class.

Total increase in marks = (x * 1/2) = x/2

x/2 = (83 – 63) => x/2 = 20 => x = 40