Question

The average age of 25 girls in a class is 11.2 years and that of the remaining 15 girls is 10 years. Find the average age of all the girls in the class.

• A. 10.75 years
• B. 11.35 years
• C. 10.45 years
• D. 11.05 years

Answer 1

Answer:

A. 10.75 years

The average age of 25 girls in a class is 11.2 years Sum of ages = Average × Total number of girls = 11.2 × 25 = 280 remaining 15 girls are 10 years = 10 × 15 = 150 The total sum of ages of all 40 girls = 280 + 150 = 430 Average = 430/40 = 10.75 years