Question

In how many years will a sum of money double itself at 8 per annum

Answer 1

✬ Time = 12.5 Years ✬

Step-by-step explanation:

Given:

• Rate of interest is 8% per annum.

To Find:

• In how many years will a sum of money double itself ?

Solution: Let the sum of money (Principal) be Rs P. Therefore,

➨ Amount = Double of principal

➨ Amount = 2P

We know that Amount + Principal gives Interest.

• Here , A = 2P
• P = P
• I = To be calculated

➼ A = P + I

➼ 2P = P + I

➼ 2P – P = I

➼ P = I

Now, Formula for finding Simple Interest is

★ S.I = ( P $\times$ R $\times$ T/100) ★

$\implies{\rm }$ P = ( P $\times$ 8 $\times$ T/100 )

$\implies{\rm }$ 100P = 8P $\times$ T

$\implies{\rm }$ 100P/8P = T

$\implies{\rm }$ 12.5 = T

Hence, in 12.5 or 12(1/2) years the sum of money will double itself.

Answer 2

* Time = 12.5 Years *

Step-by-step explanation:

Given:

• Rate of interest is 8% per annum.

To Find:

• In how many years will a sum of

money double itself?

Solution: Let the sum of money

(Principal) be Rs P. Therefore,

- Amount = Double of principal

Amount = 2P

We know that Amount + Principal gives

Interest.

• Here, A = 2P

PEP

| = To be calculated

» A= P +

» 2P = P + 1

» 2P - PE

» P = 1

Now, Formula for finding Simple Interest

is

* SI = (PXRx T/100) *

P = (P x 8 x T/100)

100P = 8P XT

100P/8P = T

= 12.5 = T

Hence, in 12.5 or 12(1/2) years the sum

Hence, in 12.5 or 12(1/2) years the sumof money will double itself.