The average age of 12 girls in a class is 14 years. If 4 new girls, each aged 10 years, join the class, what will be the new average?

Question: The average age of 12 girls in a class is 14 years. If 4 new girls, each aged 10 years, join the class, what will be the new average?

Solution:
Given,
The average age of 12 girls in a class = 14 years
Sum of ages of 12 girls = (12 × 14) years
= 168 years

Sum of ages of 4 girls = (4 × 10) years
= 40 years

∴Total age of 16 girls = (168 + 40) years
= 208 years

∴ Average of ages of 16 girls = 208/16 years
= 13 years