prep 数学

pensi_112

M买了一把椅子和一个咖啡桌，然后又把这两个东西在她的店子里卖掉。her grass profit from the purchase and sale of the chair was what percantage greater than grass profit from sale 咖啡桌
(1)M paid 10% more for chair than for 咖啡桌
(2)M sold the chair for 20% more than sold 咖啡桌

wawadream

答案是E吧！

if the purchase price of the coffee table is A, then for the chiair is (1+10%)A。

if the selling price of the coffee table is B, then for the chair is (1+20%)B

the question is: {[(1+20%)B-(1+10%)A]-[B-A]}/(B-A),simplified to be (0.2B-0.1A)/(B-A),we can not get the answer.