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 the correct option.
A) 13  B) 18  C) 40  D) 82  E) 43
<gadget id="calculator">83 - 63</gadget>
<output>20</output>

<gadget id="calculator">20 * 2</gadget>
<output>40</output>

<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?
multiply(subtract(83, 63), const_2)
"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 : c"