A man borrowed ₹ 12000 for 4 yr at 7 3/ 4 per annum and a year later he again borrowed another ₹ 12000 for 3 yr at the same rate. How much should he pay at the end to settle the loans?

In the first case
P = Rs. 12000, T = 4 yr and R = 31/4 % per annum
SI = PTR/100 = (12000 x 4 x 31/4)/100 = ₹ 3720
A = (P + SI) = (12000 + 3720) = ₹ 15720
In the second case
P = ₹ 12000, T = 3 yr and R = 31/4 % per annum
SI = PTR/100 = (12000 x 3 x 31/4)/100 = ₹ 2790
A = (P + SI ) = (12000 + 2790) = ₹ 14790
∴ Total memory to be paid at the end = (15720 + 14790) = ₹ 30510