Question

suhnil deposited a sum of rs 8000 at compound interest in the bank at the rate of 18%per annum for 3 years .what interest will he get after the end of 3 years?

Answer 1

sunhil deposited a sum of rs 8000 at compound interest in the bank at the rate of 18%per annum for 3 years.
so the compound interest will be _____________
$(8000 (1 + \frac{18}{100} )^{3} ) - 8000 \\ = (8000 (1 + \frac{9}{50} ) ^{3} ) - 8000 \\ = (8000 \times \frac{59}{50} \times \frac{59}{50} \times \frac{59}{50} ) - 8000 \\ = ( \frac{1643032}{125} ) - 8000 \\ = 13144.256 - 8000 \: \: rs \\ = 5144.256 \: rs$
hope this helps..

Answer 2

Given :-

Principle amount deposited by Suhail = Rs. 8000

Annual interest rate = 18%

Time in years = 3 years

To Find :-

The interest he will get after the end of 3 years.

Solution :-

We know that,

a = Amount

p = Principle amount

r = Annual interest rate

t = Time

Using the formula,

$\underline{\boxed{\sf Amount=P \bigg( 1+\dfrac{r}{100} \bigg)^t}}$

Given that,

Principle (p) = Rs. 8000

Annual rate interest (r) = 18%

Time (t) = 3 years

Substituting their values,

⇒ a = 8000 × (1 + 18/100)³

⇒ a = 8000 × (118/100)³

⇒ a = 8000 × 1.18 × 1.18 × 1.18

⇒ a = 8000 × 1.64

⇒ a = 13120

Using the formula,

$\underline{\boxed{\sf Interest = Amount - Principal }}$

Given that,

Amount (p) = Rs. 13120

Principle (p) = Rs. 8000

Substituting their values,

⇒ 13120 - 8000

⇒ Rs. 5120

Therefore, interest he will get after the end of 3 years is Rs. 5120.