Answer:
72.5%
Explanation:
The fraction is $21.75/$30 = 0.725.
To make this a percentage, multiply by 100%:
... 0.725 × 100% = 72.5%
_____
We assume the question is correct as written: "of the regular price." The answer is the complement of this, 27.5%, if the wording is supposed to be "off the regular price."