A student's marks were incorrectly entered as 94 instead of 69. Due to this error, the average marks of the class got increased by 1.25. What is the number of students in the class?

20

Let the number of students in class be x

The sum of marks obtained by the students increased by = 94 - 69 = 25

Average marks increased by = \(\frac{25}{x}\)

⇒ \(\frac{25}{x}\) = 1.25

⇒ x = 20