Question

Find the compound interest on Rs. 12000 for 3 years at 10% per annum compounded annually. *
1 point
a) 3672
b) 3772
c) 3872
d) 3972

Answer 1

Given:

• Principal Sum, P = Rs. 12,000
• Time for interest, t = 3 yrs
• Rate of interest per annum, R = 10 %

To find:

• Compound interest, C.I. =?

Formula required:

• Formula to calculate Compound interest

        C.I. = P ( 1 + R/100 )^t - P

[ Where C.I. is compound interest, P is principal, R is the rate of interest and t is the time ]

Solution:

Using Formula

→ C.I. = P ( 1 + R/100 )^t  - P

→ C.I. = 12000 ( 1 + 10/100 )^3  -  12000

→ C.I. = 12000 ( 1 + 1/10 )^3  -  12000

→ C.I. = 12000 ( 11/10 )^3  -  12000

→ C.I. = 12000 ( 1331 / 1000 ) - 12000

→ C.I. = 15972 - 12000

→ C.I. = 3972 Rs.

Therefore,

• Compound interest on the given sum will be Rs. 3972.

Answer 2

Answer:

Given :-

• Rs 12000 for 3 years at 10% per annum compounded annually.

To Find :-

• What is the compound interest.

Formula Used :-

❶ To find amount (A) we know that,

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

❷ To find the compound interest, we know that,

$\large\green{\underline{{\boxed{\textbf{C.I\: =\: Amount\: -\: Principal}}}}}$

Solution:-

Given :

• Principal (P) = Rs 12000
• Rate of Interest (r%) = 10 %
• Time (n) = 3 years

❶ First we have to find the amount,

⇒ Amount = P( 1 + $\dfrac{r}{100}$ )³

⇒ Amount = 12000( 1 + $\sf\dfrac{\cancel{10}}{\cancel{100}}$ )³

⇒ Amount = 12000 ( 1 + $\dfrac{1}{10}$ )³

⇒ Amount = 12000( $\dfrac{11}{10}$ )³

⇒ Amount = 12000 × $\dfrac{11}{10}$ × $\dfrac{11}{10}$ × $\dfrac{11}{10}$

⇒ Amount = 12 × 11 × 11 × 11

⇒ Amount = Rs 15972

❷ Now, we have to find the compound interest,

⇒ C.I = 15972 - 12000

➠ $\small\bf{\underbrace{\blue{C.I\: = Rs\: 3972}}}$

$\therefore$ The compound interest will be $\small{\red{\bold{\underline{Rs\: 3972}}}}$. Correct options will be the option no (d) ☑.

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