Multiple choice

A pupils 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. The number of pupils in the class is____

  1. $10$
  2. $20$
  3. $40$
  4. $73$
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C Correct answer
AI explanation

Let the number of pupils be n. The total increase in marks is 83 minus 63, which equals 20. Since the average increases by 1/2, multiplying the number of pupils n by 1/2 gives the total increase of 20. Solving n divided by 2 equals 20 results in n being 40.

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