Question

The average age of all the 100 employees in an office is 29 years, where $\frac{2}{5}$ employees are ladies and the ratio of average age of men to women is 5 : 7. The average age of female employees is:

• A. 18 years
• B. 35 years
• C. 25 years
• D. none of these

Answer 1

The correct option is B 35 years

Go through options: 40 $\times$ 35 + 60 $\times$ 25 = 29 $\times$ 100
Since there are 40 ladies and 60 gents

Alternatively:
40 $\times$ 7x + 60 $\times$ 5x = 29 $\times$ 100
$\Rightarrow$ x = 5
$\therefore$ 7x = 35