First, find the amount of money one will pay for three hats without the discount. We have $\textbackslash$ 40 \times 3$ hats $=\textbackslash$ 120$. Then, find the amount of money using the discount: $40+0.9 \times 40+\frac{1}{2} \times 40=\textbackslash$ 96$. Finding the percentage yields $\frac{96}{120}=80 \textbackslash\%$ To find the percent saved, we have $100 \textbackslash\%-80 \textbackslash\%=(\text{B}) 20$ 
At the 2017 King County Fair a vendor is offering a "fair special" on hats. If you buy one hat at the regular price of $40$ dollars, you get a second hat at a $10 \textbackslash\%$ discount, and a third pair at half the regular price. James took advantage of the "fair special" to buy three hats. What percentage of the $120$ dollars regular price did he save? (adapted from 2013 AMC 8, Question \#12) 
[a] $$15$$ 
[b] $$20$$ 
[c] $$25$$ 
[d] $$30$$ 
[e] $$40$$ 