So if the dress is 25% off, that means you are paying 75% of the original price.
sale price = original price x 0.75
225 = original price x 0.75
divide both sides by 0.75 to isolate original price
225/0.75 = (original price x 0.75)/0.75
300 = original price
aand this is not my answer credits to person on top of me