Question

Find what time a sum of money double itself at 4.5% interest compounded annually?​

Answer 1

Answer:

The question does not mention the interest rate application. Is it simple or compounded.

In cse it is simple rate application, pl assume the sum as RS 100.00. You want it to be doubled means u want interest Rs 100 then it will be doubled.

Apply formula of interest

Interest=PxRxT÷100

100=100x8xT÷100

T=12.5 years

In case of annually compounded interest let us assume that Rs 100 to become 200 . Alply formula

A=P(1+R/100)^T

200=100(1+8/100)^T

200=100(27/25)^T

2=27/25^T

(1.08)^8=(1.08)^T

T=9

Thus a sum will be doubled in 12.5 years at simple interest rate and in 9 years at compound interest rate of 8% PA

You can verify the answer of compound rate as under

A=P(1+R/100)^T

200=100(1+8/100)^9

200=100(27/25)^9

2=27/25^9

2=(1.08)^9

2=2