Sushant spent $18\%$ of his monthly salary on buying electronic goods and $32\%$ of the monthly salary on repair work in his house. Out of the remaining amount, he invested $42\%$ in a fixed deposit. If he was left with $\text{Rs. }12,325$, how much is his annual salary?

Let the monthly salary of Sushant be $X$.
Total percentage spent initially $=18\%+32\%=50\%$
Remaining percentage of monthly salary $=100\%-50\%=50\%$
Remaining amount $=0.50X$

Out of this remaining amount, he invests $42\%$ in a fixed deposit.
Therefore, the percentage left with him is:

$$100\%-42\%=58\%$$

According to the question:

$$58\%\text{ of }(50\%\text{ of }X)=12325$$

$$\frac{58}{100}\times \frac{50}{100}\times X=12325$$

$$0.58\times 0.50\times X=12325$$

$$0.29X=12325$$

$$X=\frac{12325}{0.29}=42500$$

Thus, his monthly salary is $\text{Rs. }42,500$.
To find his annual salary:

$$\text{Annual Salary}=42500\times 12=\text{Rs. }5,10,000$$