Question

Find the amount and the compound interest on Rs 12800 for 1 year at $7\frac{1}{2}\%$ per annum, compounded semi-annually.

Answer 1

$\text{Principal (P) = Rs. 12800}\text{Rate (R)}=7\frac{1}{2}\%p.a.=\frac{15}{4}\%\text{half yearly}\text{Period (n) = 1 year or 2 half years}\therefore \text{Amount (A)}={(1+\frac{R}{100})}^n=Rs.12800{(1+\frac{15}{4\times 100})}^2=Rs.12800\times \frac{83}{80}\times \frac{83}{80}=Rs.13778\therefore \text{C.I = A - P}\text{= Rs. 13778 - Rs. 12800 = Rs. 978}$