Question

What sum of money borrowed on 24th May will amount to Rs. 10210.20 on 17th October of the same year at 5 percent per annum simple interest.

Answer 1

A= Rs. 10210.20
R= 5% P.A.
T= May+June+July+August+Sept+Oct.
=7+30+31+31+30+17
=$\frac{146}{365}$ days=$\frac{2}{5}$ year
We know that:
P+I=A
$\Rightarrow P+\frac{P\times T\times R}{100}=A$
\Rightarrow P \left ( 1+\frac{R \times T}{100} \right )=A \)
$\Rightarrow P(1+\frac{5\times \frac{2}{5}}{100})=Rs.10210.20$
$\Rightarrow P(1+\frac{2}{100})=Rs.10210.20$
$\Rightarrow P\times \frac{102}{100}=Rs.10210.20$
$\Rightarrow P=Rs.10210.20\times \frac{100}{102}$
$\Rightarrow P=Rs.\frac{1021020}{102}$
$\Rightarrow P=Rs.10010$
$\therefore$ Money to be borrowed=Rs. 10010