Question

If difference between C.l.and S.I.is Rs. 21 with 5% annual rate in 2 years.Find the Principle?​

Answer 1

Given :

Difference : ₹21

Rate of interest : 5%

Time : 2 years

To find :

The principle amount.

Solution :

We can find the principle amount by the formula of difference.

Principle :

$\sf \dashrightarrow Difference = Principle \bigg( \dfrac{Rate}{100} \bigg)^{Time}$

$\sf \dashrightarrow 21 = P \bigg( \dfrac{5}{100} \bigg)^{2}$

$\sf \dashrightarrow 21 = P \bigg( \dfrac{1}{20} \bigg)^{2}$

$\sf \dashrightarrow 21 = P \bigg( \dfrac{1^2}{20^2} \bigg)$

$\sf \dashrightarrow 21 = P \bigg( \dfrac{1}{400} \bigg)$

$\sf \dashrightarrow P = 21 \div \dfrac{1}{400}$

$\sf \dashrightarrow P = 21 \times \dfrac{400}{1}$

$\sf \dashrightarrow P = \dfrac{21 \times 400}{1}$

$\sf \dashrightarrow P = \dfrac{8400}{1}$

$\sf \dashrightarrow P = 8400$

Hence, the principle amount is ₹8400.