Answer:
10%
Explanation:
We know that if a shirt is on sale for 20% off that means that the shirt's value is 80% of what it used to be.
We can divide 80% by 8 to find out how much 10 dollars is, so you do 8/8=1. Then you do 1*10 (or 10%*10) = $10 (or 100%)
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