Given:
A class has 30 boys and 20 girls.
The average age of boys and girls is 11 and 12 respectively.
To Find:
The average age of the whole class.
Solution:
Boys = No. of boys × Age
Boys = 30 × 11 = 330
Girls = No. of girls × Age
Girls = 20 × 12 = 240
Average Age = Boys + Girls / Total no. of boys and girls
Average Age = 330 + 240 / 50
Average Age = 570 / 50
Average Age = 11.4
Answer:
Average age of of the whole class is 11.4 .
