Answer:
The discount price for a T-shirt cost $14.40.
Explanation:
There are more than one ways to solve this problem, I used this method, but your teacher/instructor may uses different method.
First, you will need to find the 1% is, so what I do is to $18 divide 100% (which will split 18 into every single percentage representing). You should get 0.18.
Then, you will multiple 20 from 0.18, that mean you are finding the amount of 20% discount. You should get 3.6.
Now that we found the amount of discount, we need to apply it. We can do that by the orginal price, which is $18, and minus the 20% discount, which is $3.6, (18-3.6=14.4).
$14.4 will be the discounted price for that T-shirt.
I hope that helped!