Question

find the compound interest on Rs.4000 for 2 years at the rate of 10% annum interested​

Answer 1

GIVEN :-

• Principal , P = Rs. 4000.
• Time , n = 2 years.
• Rate , R = 10 %.

TO FIND :-

• Compound Interest , C.I .

SOLUTION :-

As we know that the formula for finding the compound interest is given by,

$\\ : \implies \displaystyle \sf \: C.I = P \Bigg[\bigg(1 + \dfrac{R}{100}\bigg)^{n} - 1\Bigg]$

$: \implies \displaystyle \sf \: C.I = 4000 \Bigg[\bigg(1 + \dfrac{10}{100}\bigg)^{2} - 1\Bigg]$

$: \implies \displaystyle \sf \: C.I = 4000 \Bigg[\bigg( \dfrac{100 + 10}{100}\bigg)^{2} - 1\Bigg]$

$: \implies \displaystyle \sf \: C.I = 4000 \Bigg[\bigg( \dfrac{110}{100}\bigg)^{2} - 1\Bigg]$

$: \implies \displaystyle \sf \: C.I = 4000 \Bigg[ \dfrac{12100}{10000} - 1\Bigg]$

$: \implies \displaystyle \sf \: C.I = 4000 \Bigg[ \dfrac{12100 - 10000}{10000} \Bigg]$

$: \implies \displaystyle \sf \: C.I = 4000 \Bigg[ \dfrac{2100 }{10000} \Bigg]$

$: \implies \displaystyle \sf \: C.I = 4000 \times \frac{2100}{10000}$

$: \implies \displaystyle \sf \: C.I = 4 \times \frac{2100}{10}$

$: \implies \displaystyle \sf \: C.I = 210 \times 4$

$: \implies \underline{ \boxed{\displaystyle \sf \: \bold{ C.I = 840}}}$

Hence the required compound interest is Rs. 840.

Answer 2

Given

• The compound interest on Rs.4000 for 2 years at the rate of 10% annum interested.

We Find

• The Compound Interest by given question

We Know

We used Formula :-

$\begin{gathered}\\ \implies \displaystyle \sf \: C.I = P \Bigg[\bigg(1 + \dfrac{R}{100}\bigg)^{n} - 1\Bigg] \\ \\ \\\end{gathered}$

According to the question

$\begin{gathered}\\ \implies \displaystyle \sf \: C.I = P \Bigg[\bigg(1 + \dfrac{R}{100}\bigg)^{n} - 1\Bigg] \\ \\ \\\end{gathered}$

$\begin{gathered}\implies \displaystyle \sf \: C.I = 4000 \Bigg[\bigg( \dfrac{100 + 10}{100}\bigg)^{2} - 1\Bigg] \\ \\ \\\end{gathered}$

$\begin{gathered} \implies \displaystyle \sf \: C.I = 4000 \Bigg[\bigg( \dfrac{110}{100}\bigg)^{2} - 1\Bigg] \\ \\ \\\end{gathered}$

$\begin{gathered} \implies \displaystyle \sf \: C.I = 4000 \Bigg[ \dfrac{12100}{10000} - 1\Bigg] \\ \\ \\\end{gathered}$

$\begin{gathered}\implies \displaystyle \sf \: C.I = 4000 \Bigg[ \dfrac{12100 - 10000}{10000} \Bigg] \\ \\ \\\end{gathered}$

$\begin{gathered} \implies \displaystyle \sf \: C.I = 4000 \Bigg[ \dfrac{2100 }{10000} \Bigg] \\ \\ \\\end{gathered}$

$\begin{gathered} \implies \displaystyle \sf \: C.I = 4000 \times \frac{2100}{10000} \\ \\ \\\end{gathered}$

$\begin{gathered} \implies \displaystyle \sf \: C.I = 4 \times \frac{2100}{10} \\ \\ \\\end{gathered}$

$\begin{gathered} \implies \displaystyle \sf \: C.I = 210 \times 4 \\ \\ \\\end{gathered}$

$\begin{gathered} \implies \displaystyle \sf \: \bold{ C.I = 840} \\ \\\end{gathered} \\ \\ </p><p></p><p></p><p></p><p>$

Hence, Compound interest is Rs. 840.