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Q.

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?

 A.

570

 B.

420

 C.

690

 D.

640

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Solution:
Option(B) is correct

The total salary amount = $15 \times 600 = 9000$

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 i.e., 12 workers, 2 old managers and 1 new manager = $580\times 15=8700$

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 $15\times 20=300$.

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


(4) Comment(s)


Sri Devi
 ()

1) (12w+3.720)/15=600

...... avg salary of 12 workers and 3 managers (=15 employees)

w=570 i.e., salary of one worker is calculated :)

2) ((12*570)+(2*720)+x)/15 = 580

here, x is the salary of the new joinee and equals 420 :)



Sri Devi
 ()

1) (12w+3.720)/15=600

...... avg salary of 12 workers and 3 managers (=15 employees)

w=570 i.e., salary of one worker is calculated :)

2) ((12*570)+(2*720)+x)/15 = 580

here, x is the salary of the new joinee :)



Paramjot
 ()

""Therefore, the salary of 12 workers and the remaining 2 managers:

=9000−720=8280""

This part is Useless. No need to calculate.



Naveen
 ()

The solution can be given in a brief manner: The total salary of 15 employees before the manager left:

$= 600 \times 15 = 9000$

Total salary of 15 employees after the new manager joined $= 8700$

The difference between old manager's and new manager's salary $= 300$

so the new managers salary:

$= 720 -300 $

$=\textbf{420}$