Question

If the simple interest on a certain sum of money for $15$ months at $7\frac{1}{2}\%p.a.$ exceeds the simple interest on the same sum for $8$ months at $12\frac{1}{2}\%$ p.a. by Rs. $32.50$, the sum is

• A. Rs. $3750$
• B. Rs. $3520$
• C. Rs. $3120$
• D. Rs. $3010$

Answer 1

The correct option is C Rs. $3120$

Let the required sum be Rs. $x$.

Then, $\frac{x\times 15\times 15}{12\times 2\times 100}-\frac{x\times 8\times 25}{12\times 2\times 100}=32.50$
$\Rightarrow \frac{225x-200x}{2400}=32.50$
$\Rightarrow 25x=32.50\times 2400$
$\Rightarrow x=\frac{32.50\times 2400}{25}=$ Rs. $3120$.