Question

what will be compound interest on 30000 at 20%p.a. compounded annually for 3 years​
i want method the answer should 21840 please guys iwill give brainlist answer ,rate ,thanks​

Answer 1

• Compound interest is 21840

Step-by-step explanation:

Given:-

• Principal is 30000.
• Rate of interest is 20%.
• Time period is 3 years.

To find:-

• Compound interest.

Solution:-

• We do not have amount for compound interest. So, first we will find Amount.

• Here, Interest is Compounded annually.

So,

$\boxed{ \sf \bold{ Amount = P \bigg(1 + \frac{r}{100}\bigg) ^{n} }}$

Where,

• P is principal, r is rate of interest and n is time period.

So, Put P, n and r in formula :

$\sf \longrightarrow 30000 \times \bigg(1 + \dfrac{20}{100} \bigg)^{3}$

$\sf \longrightarrow 30000 \times \bigg( \dfrac{100 + 20}{100} \bigg)^{3}$

$\sf \longrightarrow 30000 \times \bigg( \dfrac{120}{100} \bigg)^{3}$

$\sf \longrightarrow 3 \cancel{00} \cancel{00} \times \dfrac{120}{1 \cancel{00}} \times \dfrac{120}{1 \cancel{00}} \times \dfrac{120}{100}$

$\sf \longrightarrow 3 \times \cancel{\dfrac{1728000}{100} }$

$\sf \longrightarrow 3 \times 17280$

$\sf \longrightarrow \purple{ \boxed{ \sf \bold{51840}} \star}$

Amount is 51840

Now,

$\boxed{ \sf \bold{ Compound\: interest = A-P}}$

$\sf \longrightarrow 51840 - 30000$

$\sf \longrightarrow \red{ \boxed{ \sf \bold{21840}} \bigstar}$

Therefore,

Compound interest is 21840 .

Answer 2

Answer:

Given :-

• Principal (P) = Rs 30000
• Rate of Interest (r%) = 20 %
• Time (n) = 3 years

To Find :-

• What will be the compound interest.

Formula Used :-

❶ To find the amount we know that,

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

where

• A = Amount
• P = Principal
• r = Rate of Interest
• n = Time

❷ To find compound interest we know that,

$\boxed{\bold{\large{C.I\: =\: Amount\: -\: Principal}}}$

Solution :-

Given :

• Principal (P) = Rs 30000
• Rate of Interest (r%) = 20 %
• Time (n) = 3 years

According to the question by using the formula we get,

⇒ A = $30000 \times \bigg(1 + \sf\dfrac{\cancel{20}}{\cancel{100}}\bigg)^{3}$

⇒ A = $30000 \times \bigg(1 + \dfrac{1}{5}\bigg)^{3}$

⇒ A = $30000 \times \bigg(\dfrac{6}{5}\bigg)^{3}$

⇒ A = $30000 \times \dfrac{6}{5} \times \dfrac{6}{5} \times \dfrac{6}{5}$

⇒ Amount = $\sf\dfrac{\cancel{6480000}}{\cancel{125}}$

➠ A = Rs 51840

Hence, the amount will be Rs 51840

❷ Now, we have to find the compound interest,

⇒ C.I = 51840 - 30000

➣ C.I = Rs 21840

$\therefore$ The compound interest will be Rs 21840 .