Question

If the simple interest on a certain sum of money for $15$ months at $7\frac{1}{2}\%$ per annum exceed the simple interest on the same sum for $8$ months at $12\frac{1}{2}\%$ per annum by Rs. $32.50$, then find the sum of money (in Rs.).

Answer 1

Let the sum be $x.$

Using formula,

$I=\frac{PRT}{100}=\frac{x\times \frac{15}{12}\times \frac{15}{2}}{100}-\frac{x\times \frac{8}{12}\times \frac{25}{2}}{100}=32.50$

$\Rightarrow \frac{25x}{2400}=32.50$

$\Rightarrow x=\frac{32.50\times 2400}{25}=3120$

$\therefore$ Required sum $=$Rs.$3120$