Question

Radhika borrowed Rs.12000 from her friends. Out of which Rs.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

Answer-

The total interest after 3 years is Rs.5760 .

Solution-

Total money borrowed = Rs.12000

Out of those Rs.4000 is of 18% interest rate and remaining 12000-4000=8000 is of 15% interest rate.

$\text{Total interest}=\frac{P_1\times r_1\times t}{100}+\frac{P_2\times r_2\times t}{100}$

Where,

P₁ = principal amount = Rs.4000

P₂ = principal amount = Rs.8000

r₁ = rate of interest of P₁ = 18%

r₂ = rate of interest of P₂ = 15%

t = time period  = 3 years

$\text{Total interest}=\frac{4000\times 18\times 3}{100}+\frac{8000\times 15\times 3}{100}=2160+3600=5760$