Question

The compound interest on a certain sum of money at $5\%$ per annum for two years is ₹ 246. Calculate the simple interest on the same sum for three years at $6\%$ per annum.

Answer 1

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

$₹246=P[{(1+\frac{5}{100})}^2-1]$

Or, $₹246=P[\left(\frac{21}{20}\right)\times \left(\frac{21}{20}\right)-1]=P\times \left(\frac{41}{400}\right)$

Or, $P=₹\frac{246\times 400}{41}=₹2400$

Now, P=₹ 2400, r= $6\%$ p.a., t = 3 years

Using, $S.I=\frac{PRT}{100}.S.I=₹\frac{2400\times 6\times 3}{100}=₹432$