Multiple choice

The average age of 41 boys of a class is 14 years. When the age of the class teacher is included, the average age of the class becomes 15 years. Find the age of the class teacher.

  1. 66

  2. 58

  3. 56

  4. 60

  5. 41
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Total age of 41 boys = 41 * 14 = 574. Total age with teacher = 42 * 15 = 630. Teacher's age = 630 - 574 = 56.

AI explanation

The total age of the 41 boys is 41 multiplied by 14, which is 574 years. When the teacher is included, the total age of all 42 people becomes 42 multiplied by 15, or 630 years. The teacher's age is found by subtracting the boys' total age from this new sum, giving 630 minus 574, which equals 56 years.

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