Question

Find the compound interest on Rs.4,000 accrued in three years, when the rate of interest is 8% for the first year and 10% per year for second and third year.

Answer 1

Interest for the first year $$= \dfrac{P \times R \times T}{100}$$
$$= \dfrac{4,000 \times 8 \times 1}{100}$$
$$=$$ Rs.$$320$$
Amount for the first year = Rs.4,000 + Rs. 320 = Rs. 4,320
Interest for the second year $$= \dfrac{P \times R \times T}{100}$$
$$= \dfrac{4,320 \times 10 \times 1}{100}$$
$$=$$ Rs.$$432$$
Amount for the second year = Rs.4,320 + Rs. 432 = Rs. 4,752
Interest for the third year $$= \dfrac{P \times R \times T}{100}$$
$$= \dfrac{4,752 \times 10 \times 1}{100}$$
$$=$$ Rs.$$475.20$$
Amount for the third year = Rs.4,752 + Rs. 475.20 = Rs. 5,227.20
So, the compound interest = Rs. 5,227.20 - Rs.4,000 = Rs.1,227.20