Answer to Question #292998 in Financial Math for Elle

Question

William bought shares 20.3. and sold them 6.6. in the same year. The purchase price was 473 € and the selling price 639 €. What is the annual interest rate for the investment after the 30 % tax is paid from the sales profit?

Answer 1

Gross profit $=639-473=166€$

Net profit $=\frac{70}{100}×166=116.2$

Let r $=$ annual interest rate

Number of days from 20^th March to 6^th June $=78$ days

$\frac{r}{100}×\frac{78}{365}×473=116.2$

$r=114.96\%$