Arun borrowed a sum of money from Jayant at the rate of 8% per annum simple interest for the first four years, 10% per annum for the next 6 years and 12% per annum for the period beyond 10 years. If he pays a total of Rs. 12160 as interest only at the end of 15 years, how much money did he borrow?

A. Rs. 8000

B. Rs. 9000

C. Rs. 10000

D. Rs. 12000

Answer: Option A

Solution(By Examveda Team)

$$\eqalign{ & {\text{Let the sum be Rs}}{\text{. }}x \cr & {\text{Then,}} \cr} $$
$$ {\frac{{x \times 8 \times 4}}{{100}}} + {\frac{{x \times 10 \times 6}}{{100}}} \,+ $$     $$ {\frac{{x \times 12 \times 5}}{{100}}} $$   $$ = 12160$$
$$\eqalign{ & \Rightarrow 32x + 60x + 60x = 1216000 \cr & \Rightarrow 152x = 1216000 \cr & \Rightarrow x = 8000 \cr} $$