I can't figure out this formula; I need some help to write it out for a php script.
I have a value of $\$80$.
$\$80$ is the profit from a total sale of $\$100$; $ 20\%$ is the percentage margin for the respective product.
Now I just have the $\$80$ and want to get the total figure of $\$100$. How can I get the total figure and what would be the formula?
Your help is much appreciated. Thanks in advance.