I just cant figure out this formula, I thought I will take expert advice to write formula for my php script.
I have a value of $\$80$.
$\$80$ has come from a total sale of $\$100$ and $ 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