Let's look at this sentence:
a self employed person must earn 20% more than a non-self employed person
there the non-self employed person earns 18$ - it says so in the text. So we can rewrite
a self employed person must earn 20% more than 18
So, we need to find 20% more than 18.
First, what is 20% of 18?
[tex] \frac{20}{100} *18= \frac{1}{5} *18= \frac{18}{5} =3.6[/tex]
we add this to 18: 18+3.6=20.6
This must be the correct answer. Maybe there are sone extra taxes that were not mentioned in the text?