Multiple choice

The average marks per student in a class of 30 students were 45. On rechecking, it was found that marks had been entered wrongly in two cases. After correction, these marks were increased by 24 and 34 in the two cases. The corrected average marks per student would be

  1. 75

  2. 60

  3. 56

  4. 47
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Original sum = 30 * 45 = 1350. Corrected sum = 1350 + 24 + 34 = 1408. Corrected average = 1408 / 30 = 46.93, which rounds to 47.

AI explanation

The total increase in marks is 24 + 34 = 58. This increase is distributed equally among all 30 students, so the average increases by 58 / 30 = 1.93. Adding this increase to the original average of 45 gives a corrected average of 47.

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