Question

There are 9 boys and 6 girls in a hall, each holding coins in their hand. The mean number of coins for the children is 18 The mean number of coins for the boys is 14 Work out the mean number of coins for the girls.

Answer 1

24

Explanation:

Average = total number of coins / number of students

If the mean number of coins with boys is 14, the total number of coins held by boys = 14 x 9 = 126

The total number of coins held by the students = total number of children x average number of coins held by the children

15 x 18 = 270

The total number of coins held by girls = 270 - 126 =144

The mean number of coins for the girls = 144 / 6 = 24