Question

The simple interest on a deposit of ₹2400 is ₹60 more than the interest on a deposit of ₹2000 for a period of 3 years at the same rate percent. Find the rate of interest.

Answer 1

Let the rate be x% per annum

In first case:
P= ₹. 2400
R= x%
T= 3 years
$interest=\frac{P\times T\times R}{100}$
$=₹\frac{2400\times x\times 3}{100}$
$=₹72x$
In second case:
P= ₹ 2000
R=x%
T= 3 years
$interest=\frac{P\times T\times R}{100}$
$=₹\frac{2000\times x\times 3}{100}$
$=₹60x$
According to the statement,

$\Rightarrow 72x-60x=60$
$\Rightarrow 12x=60$
$x=\frac{60}{12}$
$\Rightarrow x=5$
$\therefore$ Rate = 5%