Question

Mark (✓) against the correct answer
In what time will Rs 8000 amount to Rs 8360 at 6% per annum simple interest?

(a) 8 months
(b) 9 months
(c) $1\frac{1}{4}$ years
(d) $1\frac{1}{2}$ years

Answer 1

(b) 9 months

$\begin{array}{l}\text{4}.\left(b\right)\\ \text{Let the time be}t\mathrm{years}.\\ \text{Principal}=\text{Rs}.\text{8}000\\ \text{Amount}=\text{Rs}.\text{836}0\\ \text{Rate}=\text{6}\%\text{per annum}\\ \text{Amount}=\text{Principal}(\text{1}+\frac{\text{Rate×Time}}{\text{100}})\\ \frac{8360}{8000}=1+\frac{6\times t}{100}\\ =>\frac{8360}{8000}-1=\frac{6t}{100}\\ =>t=\left(\frac{8360-8000}{8000}\right)\times \frac{100}{6}\\ =\frac{360}{8000}\times \frac{100}{6}\\ =\frac{6}{8}\times 12\text{months}\\ \text{= 9 months}\end{array}$