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. **