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? Select: A) 13 B) 18 C) 40 D) 82 E) 43
Let there be x pupils in the class.   Total increase in marks   = (x * 1/2) = x/2   x/2 = (83 - 63)   =&gt; x/2 = 20   =&gt; x = 40   Answer:40
<result>C</result>
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?