Correct Answer - Option 2 : Rs. 12,180
Given∶
Average monthly salary of a group of 7 workers in a factory = Rs. 2260.
Average salary becomes Rs. 3500 per month if manager salary is added.
Formula Used∶
Sum of the observation = Average × No. of observations
Calculation∶
Average salary of 7 workers = Rs. 2260
Sum of salaries of 7 workers = Rs. 2260 × 7 = Rs. 15,820
Now, if manager salary is added, then average becomes Rs. 3500
Total salary of 7 workers + manager’s salary = Rs. (3500 × 8) = Rs. 28,000
Manager’s salary = Rs. (28000 – 15820) = Rs. 12,180
∴ Rs. 12,180 is the manager’s monthly salary.