Averages - Quant/Math - CAT 2013

Question 4 the day: August 14, 2002
The question for the day is from the topic of averages.

The average monthly salary of 12 workers and 3 managers in a factory was Rs. 600. When one of the manager whose salary was Rs. 720, was replaced with a new manager, then the average salary of the team went down to 580. What is the salary of the new manager?

(1)

570

(2)

420

(3)

690

(4)

640

Solution:

The total salary amount = 15 * 600 = 9000
The salary of the exiting manager = 720.
Therefore, the salary of 12 workers and the remaining 2 managers = 9000 - 720 = 8280
When a new manager joins, the new average salary drops to Rs.580 for the total team of 15 of them.
The total salary for the 15 people - 12 workers, 2 old managers and 1 new manager = 580 *15 = 8700

Therefore, the salary of the new manager is 9000 - 8700 = 300 less than that of the old manager who left the company, which is equal to 720 - 300 = 420.

Another alternate method of doing the problem is as follows:

The average salary dropped by Rs.20 for 15 of them. Therefore, the overall salary has dropped by 15*20 = 300.

Therefore, the new manager's salary should be Rs.300 less than that of the old manager = 720 - 300 = 420.