Multiple choice

In a class, there are 24 boys whose average age decreases by 3 months when one boy aged 18 years is replaced by a new boy. Find the age of the new boy.

  1. 8 years

  2. 10 years

  3. 12 years

  4. 14 years
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Total decrease in age = 24 boys * 3 months = 72 months = 6 years. The new boy is 18 - 6 = 12 years old.

AI explanation

A decrease of 3 months in the average age of 24 boys means the total age decreases by 24 multiplied by 3 months, which is 72 months, or 6 years. This total decrease happens because the new boy is younger than the 18-year-old boy he replaced. The age of the new boy is therefore 18 minus 6, which equals 12 years.

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