Question

in how many years will Rs 4000 amounts to Rs 5324 at 10% per annum compound interest

Answer 1

CI=p {(1+r)^n-1}

5324-4000=4000 {(1+10/100)^n}-4000

5324=4000 (1+1/10)^n

5324/4000=(11/10)^n

1331/1000=(11/10)^n

(11/10)^3=(11/10)^n

n=3

hence 3 years

Answer 2

Answer:

3  years

Step-by-step explanation:

Given : Principal = Rs.4000

            Amount = Rs.5324

           Rate of interest = 10% =0.1

To find:In how many years will Rs 4000 amounts to Rs 5324 at 10% per annum compound interest?

Solution:

Let the time be t

No. of compounds =n =1

Formula : $A =P(1+\frac{r}{n})^{nt}$

$5324 =4000(1+0.1)^{t}$

$\frac{5324}{4000}=(1.1)^{t}$

$1.331=(1.1)^{t}$

$(1.1)^3=(1.1)^{t}$

So, t =3

Hence Rs 4000 amounts to Rs 5324 at 10% per annum compound interest in 3 years.