Ram and Laxman started business on 1st Jan 2020 with a capital of $\text{Rs. }1,20,000$ and $\text{Rs. }80,000$ respectively. Ram introduced $\text{Rs. }50,000$ to the firm on 1st July 2020 as additional capital. If the rate of interest is $15\%\text{ p.a.}$, assuming that accounts are closed as per calendar year, then the Interest payable to Ram on Capital would be:

To find the interest payable to Ram on his capital, we calculate the interest on his opening capital and additional capital based on the time period they were utilized during the calendar year (January 1, 2020 to December 31, 2020).Interest on Opening Capital:
Ram's initial capital of $\text{Rs. }1,20,000$ was used for the entire year (12 months).
$$\text{Interest}=1,20,000\times \frac{15}{100}\times \frac{12}{12}=\text{Rs. }18,000$$
Interest on Additional Capital:
Ram introduced an additional $\text{Rs. }50,000$ on 1st July 2020, which was used for 6 months (from 1st July to 31st December).
$$\text{Interest}=50,000\times \frac{15}{100}\times \frac{6}{12}=\text{Rs. }3,750$$
Total Interest Payable to Ram:
$$\text{Total Interest}=18,000+3,750=\text{Rs. }21,750$$