Question

Radhika borrowed ₹ 12000 from her friends. Out of which ₹ 4000 were borrowed at 18% and the remaining at 15% rate of interest per annum. What is the total interest after 3 years?

Answer 1

For first-year interest, we have

P₁ = ₹ 4000, R₁ = 18% and T₁ = 3 years

∵ `I_1 = (P_1 xx R_1 xx T_1)/100`

∴ `I_1 = (4000 xx 18 xx 3)/100` = ₹ 2160

For second-year interest,

P₂ = 12000 – 4000 = ₹ 8000

R₂ = 15% and T₂ = 3 years

∵  `I_2 = (P_2 xx R_2 xx T_2)/100`

∴  `I_2 = (8000 xx 15 xx 3)/100` = ₹ 3600

Hence, after 3 years, total interest = I₁ + I₂ = 2160 + 3600 = ₹ 5760