Question

求问一条GMAT数学数据充分题。。。如果能解的话请列出式子。谢谢哦~~

A home owner must pick between paint A, which costs $6.00 per liter, and paint B, which cost $4.50 per liter. Paint B takes one-third longer to apply than paint A. If the homeowner must pay the cost of labor at the rate of $36 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 labor.

Answer 1

根据条件1，假设墙体面积为1，刷每literA的时间为n，则：刷这面墙，需1/4literA或1/3literB
若选用A，cost=6x(1/4)+(1/4)nx36=1.5+9n
若选用B，cost=4.5x(1/3)+(1/3)x(4/3)nx36=1.5+16n
明显costB>costA，选用A。
条件2不知道两者每liter能刷多大面积的墙，所以不充分。

综上所述，最终答案选择A，statement(1) alone is sufficient,but statement(2) alone is not sufficient.

Answer 2

A:40L油漆，100h时间
B:30L油漆，400/3h时间
A:40*6+36*100=3840
B:30*4.5+36*400/3=4935>3840
故选A
不好意思，英文水平不行，也不知道读对题没。