Multiple choice

A school has four sections of chemistry in class XII having $40, 35, 45$ and $42$ students. The mean marks obtained in Chemistry test are $50, 60, 55$ and $45$ respectively for the four sections. The overall average of marks per students is -

  1. $53$
  2. $43$
  3. $55.3$
  4. $52.25$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Total marks = (40 * 50) + (35 * 60) + (45 * 55) + (42 * 45) = 2000 + 2100 + 2475 + 1890 = 8465. Total students = 40 + 35 + 45 + 42 = 162. Average = 8465 / 162 = 52.25.

AI explanation

To find the overall average using the weighted mean method, multiply the number of students by the mean marks for each section to get their total marks, resulting in 2000, 2100, 2475, and 1890. Adding these totals gives a combined sum of 8465 marks for all 162 students. Dividing this total sum of 8465 by the total of 162 students yields an overall average of 52.25 marks per student.

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