[求助]Prep-PS-1-62

chiachen1223 · 发表于 2009-7-14 20:16:00

求助一題:

Alice's take-home pay last year was the same each month, and she saved the same fraction of her take-home pay each month. The total amount of money that she had saved at the end of the year was 3 times the amount of that portion of her monthly take-home pay that she did not save. If all the money that she saved last year was from her take-home pay, what fraction of her take-home pay did she save each month?

(A) 1/2

(B) 1/3

(C) 1/4

(D) 1/5

(E) 1/6

正解(D)

請各位幫忙解釋為何是(D)!謝謝!!

alan722 · 发表于 2009-7-14 20:34:00

假设每个月拿回家为X，存的百分比为N， The total amount of money that she had saved at the end of the year was 3 times the amount of that portion of her monthly take-home pay that she did not save 这句话的意思用方程写出来就是

X*N*12=3*（1-N）*X

justbp · 发表于 2009-7-14 20:55:00

这倒题目有个地方需要读清楚，那就是LS说的部分！
我用个直接数字带入的方法可能简单一些～
假设一下，全年没有省的钱为1，省的钱是 1/12×3= 1/4
这样就可以推出：全年总的take-home的钱是：1/4 + 1= 5/4, 题目问的是每个月省的钱占每月take-home的比例，
则： (1/4/12) / (5/4/12)= 1/5 (其实12不用除，因为它是分子分母同时除的数）

[求助]Prep-PS-1-62

[求助]Prep-PS-1-62

所属分类: GMAT考试

正在浏览此版块的会员 ()

浏览过的版块