Question

Find the compound interest on Rs. 1000 for two years at 4% per annuall.​

Answer 1

Answer :-

• The compound interest is Rs 81.6.

To find :-

• The compound interest on Rs 1000 for two years at 4% per annum.

Solution :-

• Before finding the compound interest, let's find the amount!

We know that :-

$\underline{ \boxed{\sf Amount = Principal \left(1 + \dfrac{Rate}{100} \right)^{Time}}}$

Here,

• Principal = Rs 1000.
• Rate = 4% per annum.
• Time = 2 years.

Therefore :-

$\longrightarrow\rm Amount = 1000 \left( 1 + \dfrac{4}{100} \right)^{2}$

$\longrightarrow\rm Amount = 1000 \left(1 + \dfrac{1}{25} \right)^{2}$

$\longrightarrow\rm Amount = 1000 \left( \dfrac{1 \times 25 + 1 \times 1}{25} \right)$

$\longrightarrow\rm Amount = 1000 \left( \dfrac{25 + 1}{25} \right)^{2}$

$\longrightarrow\rm Amount = 1000 \left( \dfrac{26}{25} \right)^{2}$

$\longrightarrow\rm Amount = 1000 \times \dfrac{26}{25} \times \dfrac{26}{25}$

$\longrightarrow\rm Amount = 1000 \times \dfrac{676}{625}$

$\longrightarrow\rm Amount = \dfrac{676000}{625}$

$\longrightarrow\overline{ \boxed{ \rm Amount = Rs \: 1081.6}}$

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• Now, let's find the compound interest!

We know that :-

$\underline{ \boxed{ \sf CI = Amount - Principal}}$

Where,

• CI = Compound Interest.

Here,

• Amount = Rs 1081.6.
• Principal = Rs 1000.

Therefore,

$\longmapsto\bf CI = 1081.6 - 1000$

$\longmapsto\bf CI = Rs \: 81.6$

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Hence :-

• The compound interest is Rs 81.6.