Q8 pls ans fast experts
Q.8. Find the C.I. on Rs. 60,000 at the rate of 8 % p.a. for 1.5 years when the interest is compounded half-yearly.

Dear Student,

Annual compound interest including principal sum can be obtained as

$A = P{\left(1+\frac{r}{n}\right)}^{nt}$     (1), where A is the final amount, P is the principal, r is the rate of interest (in %), t is the no. of years the principal is invested/loaned for and n is the no. of times the interest is compounded per year.

Now total compound interest can be obtained from,

C.I = A - P = $P{\left(1+\frac{r}{n}\right)}^{nt}-P$.

For the present case, P = 60,000 , r = 8% = 0.08, n = 2 (half yearly means interest compounded two times in an year), t = 1.5


Then, C.I =   

$$\begin{gathered} 60000{\left(1+\frac{0.08}{2}\right)}^{\left(2\times 1.5\right)} - 60,000 \\ = 60000\left({\left(1+0.04\right)}^3- 1\right) \\ = 60000\times 0.125 = 7500 \end{gathered}$$

The C.I  = 7500 /-


Regards