Correct Answer - Option 1 : 15
Given:
The average salary per employee in the marketing department of MNC is Rs. 400.
The average salary of 10 senior employees = Rs. 550 per employee
The average salary of the remaining staff = Rs. 100 per employee.
Concepts used:
Average salary = (Total salary of all employees)/(Number of employees)
Calculation:
Let the total number of employees in the marketing department of MNC be x.
Total salary of all employees = Rs. 400 × x = Rs. 400x
Total salary of all senior employees = Rs. 550 × 10 = Rs. 5,500
Remaining staff = Total number of employees - Number of senior employees = x – 10
The average salary of the remaining staff is Rs. 100 per employee.
Total salary of remaining employees = Rs. (100x – 1,000)
Total salary of all employees = Total salary of all senior employees + Total salary of remaining employees
⇒ 400x = 5,500 + 100x – 1,000
⇒ 400x – 100x = 4,500
⇒ 300x = 4,500
⇒ x = 4,500/300
⇒ x = 15 employees
∴ There are total 15 employees working in the marketing department of MNC.