Question

find the compound interest on Rs.12000 for 3years at 10% per annum compounded annually

Plz answer fastly​

Answer 1

Answer:

• Compound interest = Rs.3972

Explanation:

We know,

→ C.I. = Amount - principal

Using amount formula,

$\implies \rm \: A = p \bigg(1 + \dfrac{r}{100} \bigg)^{n}$

Where,

• p(principal) = Rs.12,000
• r(rate) = 10% p.a.
• n(time) = 3 yrs.

Substitute the given values,

$\rm = 12000\bigg(1 + \dfrac{10}{100} \bigg)^{3}$

$\rm = 12000\bigg(1 + \dfrac{1}{10} \bigg)^{3}$

$\rm = 12000\bigg( \dfrac{11}{10} \bigg)^{3}$

$\rm = 12000 \times \dfrac{1331}{1000}$

$\rm = 12 \times 1331$

$= 15972$

∴ Compund interest :-

$= 15972 - 12000$

$= 3972$

∴ Required answer: Rs.3972

__________________________________________

Answer 2

Answer:

Given :-

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

To Find :-

• What is the compound interest.

Solution :-

☆ First, we have to find the amount :

As we know that :

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

where,

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

So,

Given :

• Principal = Rs 12000
• Rate of Interest = 10%
• Time Period = 3 years

According to the question by using the formula we get,

$\implies \sf A =\: 12000\bigg(1 + \dfrac{10}{100}\bigg)^3$

$\implies \sf A =\: 12000\bigg(\dfrac{100 \times 1 + 10}{100}\bigg)^3$

$\implies \sf A =\: 12000\bigg(\dfrac{100 + 10}{100}\bigg)^3$

$\implies \sf A =\: 12000\bigg(\dfrac{110}{100}\bigg)^3$

$\implies \sf A =\: 12000\bigg(\dfrac{110}{100} \times \dfrac{110}{100} \times \dfrac{110}{100}\bigg)$

$\implies \sf A =\: 12000\bigg(\dfrac{110 \times 110 \times 110}{100 \times 100 \times 100}\bigg)$

$\implies \sf A =\: 12000\bigg(\dfrac{1331000}{1000000}\bigg)$

$\implies \sf A =\: 12000 \times \dfrac{1331\cancel{000}}{1000\cancel{000}}$

$\implies \sf A =\: 12{\cancel{000}} \times \dfrac{1331}{1\cancel{000}}$

$\implies \sf A =\: 12 \times 1331$

$\implies \sf\bold{A =\: Rs\: 15972}$

Hence, the amount is Rs 15972 .

☆ Now, we have to find the compound interest :

As we know that :

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

where,

• A = Amount
• P = Principal

Given :

• Amount = Rs 15972
• Principal = Rs 12000

According to the question by using the formula we get,

$\dashrightarrow \sf Compound\: Interest =\: Rs\: 15972 - Rs\: 12000$

$\dashrightarrow \sf\bold{Compound\: Interest =\: Rs\: 3972}$

$\therefore$ The compound interest is Rs 3972 .