Question

Natesh borrowed some money at rate $6\%$ p.a. for the first $3$ years, $9\%$ p.a. for the next five years and $13$ p.a. beyond $8$ years. The above are all simple interest rates. If Natesh pays a total of Rs. $8160$ as an interest after $11$ years , how much money did he borrow?

• A. Rs. $8000$
• B. Rs. $10000$
• C. Rs. $12000$
• D. Rs. $14000$

Answer 1

The correct option is A Rs. $8000$

Let he borrowed principal $P$
Interest for first $3$ years $=\frac{PTR}{100}=\frac{P\times 3\times 6}{100}=\frac{18P}{100}$

Interest for next $5$ years$=\frac{P\times 5\times 9}{100}=\frac{45P}{100}$

Interest for next $3$ years $=\frac{P\times 3\times 13}{100}=\frac{39P}{100}$

Total Interest $=8160$
$\Rightarrow \frac{18P}{100}+\frac{45P}{100}+\frac{39P}{100}=8160$
$\Rightarrow 18P+45P+39P=816000$

$\Rightarrow 102P=816000$
$\Rightarrow P=$ Rs. $8000$