Question

The compound interest on a certain sum of money at 10% per annum for two years is ₹315. Calculate the simple interest on the same sum for four years at 12% per annum.

• A. ₹700
• B. ₹750
• C. ₹720
• D. ₹800

Answer 1

The correct option is C

₹720

Using $C.I=P[{(1+\frac{r}{100})}^n-1]$,we get

$₹315=P[{(1+\frac{10}{100})}^2-1]$$\Rightarrow ₹315=P[\left(\frac{11}{10}\right)\times \left(\frac{11}{10}\right)-1]=P\times \left(\frac{21}{100}\right)$

$\Rightarrow P=₹\frac{315\times 100}{21}=₹1500$

Now, P = ₹1500, R = $12\%$ p.a., t = 4 years.
$S.I.=\frac{PRT}{100}.S.I=Rs.\frac{1500\times 12\times 4}{100}=₹720$