The marks obtained by 5 students are 21, 27, 19, 26, 32. Later on 5 grace marks are added to each student. What are the average marks of the revised marks of the students?

  1. A. 26
  2. B. 30
  3. C. 31
  4. D. 32

Correct Answer: B. 30

Explanation

The initial average is \frac{21+27+19+26+32}{5} = \frac{125}{5} = 25. If a constant amount is added to each observation, the mean increases by the same amount. The new average is 25 + 5 = 30.

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