A shop has a sale of 30% off all items in stock. If the original price of a dress is £40 what would be its sale price?

Step-by-step explanWhat i usually do for these problems is because pecent is out of 100, just subtract the percent from 100 percent and multiply that ammount to the original price, so 40 * (100%-30%) = 40 * 70% or 40 * 0.7, so the answer would be 28