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: Choose the most appropriate option.
A) 10	B) 20	C) 40	D) 73	E) None of the above
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.   Answer 40
<result>C</result>
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: