Multiple choice

The present average age of n boys in Class VIII is Y years. Three new boys join the class, whose ages are Y - 1, Y - 2 and Y + 3 years. What will be the new average age (in years) of the class, when all the students are promoted to Class X(tenth)?

  1. Y

  2. n Y + 2 n + 3

  3. Y + 1

  4. Y + 2
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The three new ages total (Y - 1) + (Y - 2) + (Y + 3) = 3Y, so the average remains Y after they join. When everyone is promoted two years later, every age increases by 2, making the new average Y + 2.

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