Question

Sonia borrowed rs.30,000 from friends co-operative bank and returned an smount of 34,500 with interest after 3 years. Find the simple interest paid and rate of interest per annum.

Answer 1

Dear Student,
Here is the solution of your asked query:
$$\begin{gathered} \mathrm{Here}\mathrm{Amount}\mathrm{borrowed}=\mathrm{Rs}.30,000 \\ \mathrm{Total}\mathrm{amount}\mathrm{returned}=\mathrm{Rs}.34,500 \\ \mathrm{So}\mathrm{interest}=\mathrm{Rs}.34,500-\mathrm{Rs}.30,000=\mathrm{Rs}.4500 \\ \mathrm{Time}=3\mathrm{years} \\ \mathrm{Than},4500=\frac{\mathrm{p}\times \mathrm{r}\times \mathrm{t}}{100}=\frac{30,000\times \mathrm{r}\times 3}{100} \\ \Rightarrow 4500=\frac{30,000\times \mathrm{r}\times 3}{100} \\ \Rightarrow 900\mathrm{r}=4500 \\ \Rightarrow \mathrm{r}=\frac{4500}{900}=5 \\ \mathrm{Therefore}\mathrm{rate}\mathrm{of}\mathrm{interest}\mathrm{is}5\%\mathrm{per}\mathrm{annum} \end{gathered}$$
Regards