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 (1/2). The number of pupils in the class is:  Choose the correct option
A) 10 B) 20 C) 40 D) 73 E) 64
let x pupils in the class   by question   total increase in marks = x/2   so;x/2 = (83 - 63)   x = 2 * 20   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 (1/2). The number of pupils in the class is: