Multiple choice

There are 10 students in a class. The average score of 10 students increases by 2 when a new student replaces an old student, who scored 50 marks. What is the score of the new student?

  1. 70

  2. 75

  3. 78

  4. 88

  5. 90
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A Correct answer
Explanation

The total score increases by 2 * 10 = 20 marks. The new student's score = old student's score + increase = 50 + 20 = 70.

AI explanation

When a new student replaces an old student, the total increase in the overall marks equals the average increase multiplied by the number of students, giving 2 times 10, which is 20 marks. The new student's score equals the old student's score plus this total increase, meaning 50 plus 20, resulting in 70 marks.

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