Question

Compound interest on a certain sum of money at $5$% per annum for two years is Rs. $246$. Calculate simple interest on the same sum for $3$ years at $6$% per annum.

Answer 1

Given, $C.I.=Rs.246$
Rate of interest $r=5$%
Time $N=2years$
let the principal amount$=P$
$Amount=P{(1+\frac{R}{100})}^N=P{(1+\frac{5}{100})}^2=P\times \left({1.05}^2\right)=1.1025P$

So, $C.I.=A-P=1.1025P-P=0.1025P$

Given, $C.I.=Rs246$
$\Rightarrow 0.1025P=Rs246$
$\Rightarrow P=Rs2,400$


Now the simple interest$(S.I)$ for,
$\Rightarrow P=Rs2,400$
$N=3years$
$R=6$ %

We have $S.I.=\frac{PNR}{100}$
$=\frac{2,400\times 3\times 6}{100}$
$=24\times 3\times 6=Rs.432$