Question

If P=7000 Rs R=10% T =3years Find C.I​

Answer 1

Given

• Principal - 7000
• Rate - 10%
• Time - 3 years

To Find

We have to find C.I

• C.I = Compound Interest

Formula Using

$\Large\begin{gathered} {\underline{\boxed{ \rm {\red{ A \: = \: P \: \bigg(1 \: + \: \frac{r}{100} \: \bigg) ^{t} }}}}}\end{gathered}$

$\Large\begin{gathered} {\underline{\boxed{ \rm {\blue{ C.I \: = \: A \: - \: P }}}}}\end{gathered}$

Where ,

• A denotes Amount.
• P denotes Principal.
• R denotes rate of interest.
• t denotes time ( in years ).
• C.I denotes Compound Interest

Basic Terms

• Simple Interest = Simple interest is the method of calculating interest charged on the amount invested in a fixed deposit.

• Principle = The principal is the amount due on any debt before interest, or the amount invested before returns

• Rate = An interest rate is the percentage of principal charged by the lender for the use of its money.

• Time = Time is duration (in months or years) in Simple Interest.

Solution

✯ Here ,

$\bf \implies \: Principal \: = \: Rs. \: 7000$

$\bf \implies \: Rate \: \: of \: \:Internet \: = \: 10 \: \%$

$\bf \implies \:Time \: = \: 3 \: \: years$

$\large✯ \: {\textrm{{{\color{navy}{Calculating \: the \: Compound \: Interest}}}}} \: ✯$

☛ Now , Substuting the values.

$\bf \large \longrightarrow \: A \: = \: 7000 \: \bigg(1 \: + \: \frac{10}{100} \: \bigg) ^{3}$

$\bf \large \longrightarrow \: A \: = \: 7000 \: \bigg( \: \frac{110}{100} \: \bigg) ^{3}$

$\bf \large \longrightarrow \: A \: = \: 7 \cancel0 \cancel 0 \cancel0 \: \times \: \frac{110}{100} \: \times \: \frac{110}{10 \cancel0} \: \times \: \frac{110}{1 {\cancel0 \cancel0} }$

$\bf \large \longrightarrow \: A \: = \: 7 \: \times \: \frac{110}{100} \: \times \: \frac{110}{10} \: \times \: 110$

$\bf \large \longrightarrow \: A \: = \: 7 \: \times \: \frac{11 \cancel0}{1 \cancel0 \cancel0} \: \times \: \frac{11 \cancel0}{1 \cancel0} \: \times \: 11 \cancel0$

$\bf \large \longrightarrow \: A \: = \: 7 \: \times \: 11 \: \times \: 11 \: \times \: 11$

$\bf \large \longrightarrow \: A \: = \: 77 \: \times \: 121$

$\large \underbrace{\textrm {{{\color{red}{\bf \large \ \: Amount \: = \: 9317 \: }}}}}$

⇛ So , the amount is Rs. 9317

$\Large \purple \dag \: \underline {\rm {{{\color{orange}{For \: \: Finding \: \: C.I.}}}}} \: \purple \dag$

$\Large\begin{gathered} {\underline{\boxed{ \rm {\blue{ C.I \: = \: A \: - \: P }}}}}\end{gathered}$

☛ Now , Substuting the values.

$\bf \large \longrightarrow \: C.I \: = \: 9317 \: - \: 7000$

$\bf \large \longrightarrow \: C.I \: = \:2317$

$\large \underbrace{\textrm {{{\color{blue}{\bf \large \ \: Compound Interest \: = \:Rs. \: 2317 \: }}}}}$

⇛ So , the Compound Interest is Rs. 2317