Question

The average monthly salary of employees, consisting of officers and workers, of an organisation is Rs. 3000. The average salary of an officer is Rs. 10,000 while that of a worker is Rs. 2000 per month. If there are total 400 employees in the organisation, find the number of officers.

• A. 60
• B. 50
• C. 80
• D. 40

Answer 1

Answer: (B)

50

Answer 2

Let's take the number of officers o and number of workers w
∑$\frac{o}{o}$ = 10000
∑$\frac{w}{w}$ = 2000
∑o + ∑$\frac{w}{w+o}$ = 3000
w + o = 400 – Equation(1)
Solving this, we get
10000o + 2000w = 3000w + 3000o
So, 7o = w – Equation(2)
Putting the value of equation 2 in equation 1, we get
8o = 400
o = $\frac{400}{8}$
o = 50
Number of officers = 50
The correct option is (B)