If in the sales department of a company, the average salary per employee is Rs. 350, average salary of 10 senior employees is Rs. 450 per employee and average salary of remaining staff is Rs. 250 per employee, then what is the total number of employees working in the sales department ?

20

Let total number of employees = x

⇒ 10 x 450 + (x - 10) x 250 = 350 × x

⇒ 4500 + 250x - 2500 = 350x

⇒ 100x = 2000

⇒ x = 20