Question

Calculate the amount and the compound
interest on :
(i) Rs 6,000 in 3 years at 5% per year.
(ii) Rs 8,000 in 2 years at 15% per annum.
​

Answer 1

(¡)

Given :

• Principal = ₹6000

• Rate = 5%

• Time, n = 3 years

We know that ,

Compound Interest (CI) =

$\bold \: p(1 + \frac{r}{100} )^{n}$

So,

CI for the (i) will be

$= 6000(1 + \frac{5}{100} )^{3} \\ = 6000( \frac{105}{100} )^{3} \\ = 6000 \times \frac{105}{100} \times \frac{105}{100} \times \frac{105}{100 } \\ = 6945.75 \: rs$

Now,

Amount = Principal + Compound Internet

Amount = ₹ 6000 + 6945.75

= ₹ 12945.75

(ii)

Given :-

• Principal = ₹8000
• Rate = 15%
• Time, n = 2 years

Now, By using the formula Mentioned above

CI =

$= 8000(1 + \frac{15}{100} ) ^{2} \\ = 8000( \frac{115}{100} ) ^{2} \\ = 8000 \times \frac{115}{100} \times \frac{115}{100} \\ = 10580 \: rs$

Now,

Amount = Principal + Compound Interest

Amount = ₹ (8000 + 10580)

= ₹ 18580