Question

Find the compound interest on rs 20000 for 3 years at 10% annum

Answer 1

Answer :-

Rs.6620

Explanation :-

Given :

Principle = Rs.20000

Time = 3 years

Rate = 10%

To Find :

Compound Interest (CI) = ?

Solution :

We know,

Compound Interest = Amount - Principle

We don’t know amount here,so let’s find it first.

We know,

$\boxed{\sf{} A=P\bigg(1+\dfrac{r}{100}\bigg)^n}$

where,

A = amount.

P = principle

r = rate

n = time peroid

Put their values and find “A”

$\sf{}:\implies A=20000\bigg(1+\dfrac{10}{100}\bigg)^3$

$\sf{}:\implies A=20000\bigg(\dfrac{1\times 100+10\times 1}{100}\bigg)^3$

$\sf{}:\implies A=20000\bigg(\dfrac{110}{100}\bigg)^3$

$\sf{}:\implies A=20000\bigg(\dfrac{11}{10}\bigg)^3$

$\sf{}:\implies A=20000\bigg(\dfrac{1331}{1000}\bigg)$

$\sf{}:\implies A=20000\times \dfrac{1331}{1000}$

$\sf{}:\implies A=20\times \dfrac{1331}{1}$

$\sf{}\therefore A=Rs.26620$

Compound Interest = Amount - Principle

= 26620 - 20000

∴ Rs.6620

Therefore,compound interest is equal to Rs.6620