Question

The average monthly salary of 20 workers in an office is ₹ 45900. If the manager's salary is added, the average salary becomes ₹ 49200 per month. What's manager's monthly salary?

Answer 1

Average monthly salary of 20 workers = Rs 45900
Sum of the monthly salaries of 20 workers = $\mathrm{Rs}\left(45900\times 20\right)=\mathrm{Rs}918000$
By adding the manager's monthly salary, we get:
Average salary = Rs 49200
Now,
Let the manager's monthly salary be Rs x.
Thus, we have:

$$\begin{gathered} \frac{\mathrm{Sum}\mathrm{of}\mathrm{the}\mathrm{monthly}\mathrm{salaries}\mathrm{of}20\mathrm{workers}+x}{21}=49200 \\ \Rightarrow \frac{918000+x}{21}=49200 \\ \Rightarrow 918000+x=1033200 \\ \Rightarrow x=115200 \end{gathered}$$

Therefore, the manager's monthly salary is Rs 115200.