Multiple choice

The average age of the boys in a class is $16$ years and that of the girls is $15$ years. The average age for the whole class when there are equal number of girls and boys is:

  1. $15$ years
  2. $15.5$ years
  3. $16$ years

  4. Cannot be computed with the given information
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Average = (Sum of ages of boys + Sum of ages of girls) / (Number of boys + Number of girls). Since number of boys = number of girls = n, Average = (16n + 15n) / 2n = 31n / 2n = 15.5.

AI explanation

Because there is an equal number of boys and girls, assume there is 1 boy and 1 girl. The combined sum of their ages is 16 plus 15, which equals 31. Divide this sum by 2 to get the overall average age, making the result 15.5 years.

Keep practicing — related questions