Question

In a factory, the average salary of the employees is Rs. 70. If the average salary of 12 officers is Rs. 400 and that of the remaining employees is Rs. 60, then the number of employees are ...........

• A. $396$
• B. $400$
• C. $408$
• D. $404$

Answer 1

The correct option is C $408$

$\Rightarrow$ Let total number of employees be $x$.

$\Rightarrow$ Average salary of total employee $=Rs.70$

$\Rightarrow$ Average of $12$ employees $=Rs.400$

$\Rightarrow$ Average of remaining employees $Rs.60$

$\therefore$ $70=\frac{400\times 12+(x-12)\times 60}{x}$

$\therefore$ $70x=4800+60x-720$

$\therefore$ $70x=4080+60x$

$\therefore$ $10x=4080$

$\therefore$ $x=408$

$\therefore$ Total number of employees are $408.$