sum compounded alluny
Shar
d) The difference between the annual and semi-annual compound interest on
of money is Rs 482 at the rate of 20 % per annum for 2 years. Find the sum​

Respuesta :

Answer:

Rs 20000

Step-by-step explanation:

Let the sum is x.

The rate of interest, r=20%=0.2

Time, t=2 years.

Total amount after t years, [tex]A= x \left(1+\frac{r}{n}\right)^{tn}[/tex]

The value of n when compounded annually, n=1

So, the total amount,

[tex]A_1=x \left(1+\frac{0.2}{1}\right)^{2\times 1}=x(1.2)^2[/tex]

The compound interest when compounded annually,

[tex]I_1 =x(1.2)^2-x[/tex]

The value of n when compounded semi-annually, n=2

So, the total amount, [tex]A_2 = x \left(1+\frac{0.2}{2}\right)^{2\times 2}=x(1.1)^4[/tex]

The compound interest when compounded semi-annually,

[tex]I_2 =x(1.1)^4-x[/tex]

As the difference between the annual and semi-annual compound interest on  x amount of money is Rs 482, so

[tex]I_2-I_1=482 \\\\(x(1.1)^4-x)-(x(1.2)^2-x)=482 \\\\x(1.1)^4-x(1.2)^2=482 \\\\x(1.1^4 - 1.2^2) = 482 \\\\x(0.0241) = 482 \\\\x=482/0.0241 \\\\[/tex]

x=20000

Hence, the sum is Rs 20000.