15% off a commodity can be sold 90 yuan cheaper, how much is the original price of the commodity?
85% off, that's 15% less than the original price
Original price = 90 ÷ (1-85 ℅) = 600 yuan
85% off, that's 15% less than the original price
Original price = 90 ÷ (1-85 ℅) = 600 yuan