While preparing the results of English of a class, the marks of one student got recorded as 95 in place of 57, as a result of which there was an increase in the average score by 0.95. How many students were there in the class?

40

Short trick

Required number of students = \(\frac{95 - 57}{0.5}\) = \(\frac{38}{0.95}\) = 40

Explanation

Let the total number of students be x and average marks be y.

xy + 95 - 57 = x × (y + 0.95)

xy + 38 = xy + 0.95x

0.95x = 38

x = 40