7.A store purchased a Brand C computer for the same amount that it paid for a Brand D computer and then sold them both at higher prices. The store's gross profit on the Brand C computer was what percent greater than its gross profit on the Brand D computer?
(1) The price at which the store sold the Brand C computer was 15 percent greater than the price at which the store sold the Brand D computer.
(2) The store's gross profit on the Brand D computer was $300.
A 为什么不可以？ Cost of Brand C computer = X Cost of Brand D computer = X (both same) Let the brand C computer is sold at price = SC profit => SC-X let's say PC => SC = PC+X => SC-X = PC Let the brand D computer is sold at price = SD Profit => SD-X let's say PD => SD = PD+X => SD-X=PD Question PC/PD = ? PC/PD = (SC-X)/(SD-X) Stmt1 Directly says price on Computer C is 15% greater than price on computer D SC=1.15SD => (1.15D-x)/D-X
