Calculate the interest on drawings if Ram withdrew $\text{Rs. }3,000$ per month at the beginning of each month for the whole year, with interest charged @ $9\%$ per annum.

When an equal amount is withdrawn at the beginning of every month for a full year (12 months), interest is calculated on the total drawings for an average period of $6.5$ months.Total annual drawings:
$$\text{Total Drawings}=3,000\times 12=\text{Rs. }36,000$$
Average Period calculation:
$$\text{Average Period}=\frac{\text{Months left after 1st drawing}+\text{Months left after last drawing}}{2}=\frac{12+1}{2}=6.5\text{ months}$$
Interest on Drawings calculation:
$$\text{Interest}=\text{Total Drawings}\times \frac{\text{Rate}}{100}\times \frac{\text{Average Period}}{12}$$
$$\text{Interest}=36,000\times \frac{9}{100}\times \frac{6.5}{12}$$
$$\text{Interest}=360\times 9\times \frac{6.5}{12}=30\times 9\times 6.5=270\times 6.5=\text{Rs. }1,755$$