树雪DS问题--求教？？

chloeyeah21

A home owner must pick between paint A, which costs 6 dollar per liter, and paint B, which costs 4.5 dollar per liter. Paint B takes one-third longer to apply than paint A. If the home owner must pay the cost of labour at the rate of 36 dollar per hour, which of the two paints will be cheaper to apply?
(1) the ratio of the area covered by one liter of paint A to the area covered by paint B is 4:3
(2) Paint A will require 40 liters of paint and 100 hours of labour

因为有人说 D ，老师原来说选A， 但是同学提出反驳后老师说 D 也有道理，请问一下如果是D 有没可能？ 单独（2）可以解的解题思路是什么？

asap1234

2单独貌似是可以。
条件2可以得到用A的总费用=6*40+100*36=3840
用B的话，设liter=x，4.5*X+100*36*4/3=4800+4.5X，因为X>0所以用A肯定便宜，我是这么理解。

lxy4tc

A:40*6+100*36
B: X*4.5+36*133

不知道X,2怎么解哦？

lxy4tc

沙发说的有道理

chloeyeah21

谢谢asap1234

eliasfan

按照上面的说法，那答案应该是B吧！？
由（1）不能单独确认A方案便宜啊！