Since Sameer introduced additional capital on October 1, 2019, his capital balance changed during the year. Interest needs to be calculated separately for two periods.
Period 1: April 1, 2019 to September 30, 2019 (6 months)
Capital: Rs 15,00,000
Interest = 15,00,000×1005×126
Interest = Rs 37,500
Period 2: October 1, 2019 to March 31, 2020 (6 months)
Capital: Rs 15,00,000 + Rs 3,00,000 = Rs 18,00,000
Interest = 18,00,000×1005×126
Interest = Rs 45,000
Total Interest on Sameer's Capital for 2019-20
= Rs 37,500 + Rs 45,000 = Rs 82,500
The additional capital introduced by Sameer on October 1 earns interest only for 6 months (October to March), while his original capital earns interest for the full year. This is why we calculate interest in two parts based on the time period for which different capital amounts were maintained in the business.