急问 GMATPrep 上的两题

卢精灵

GMATPREP上的几题数学  在讨论专区找了半天都没找到恳请高人指点

1、Are at least 10%of the people in Country X who are 65 years old or older employed?

(1)In Country X,13% of the population is 65 years old or olders

(2)In Country X,of the population 65 years old or older,20% of the men and 10% of the women are employed

Ans:B

我怎么觉得是选E啊

2、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 the 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 didi 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?

A1/2   B1/3  C1/4  D1/5  E1/5

Ans

这一题我理解不了 不知道在讲什么

 

[em06

lanseb8ma

1、这题题目的意思要多看两遍，把握清楚就好解题了：题目问的是“X国65岁及以上人口中，至少有10％有工作吗？”（1），缺少关于employment的信息，所以单独不行；（2），注意了！（2）所提供的条件和题干是一样的，即“在X国65岁及以上人口中”，然后又给了男性和女性有工作的比例，根据“木桶理论”，要判断“at least”，自然是根据比例最低的一类，而既然女性的比例都有10％，则对题目的回答自然是“Yes”啦，所以选B。

2、把题目的意思转化成算式，设A's take-home pay=x,save ratio=a，则根据题干第二句话所提供的条件可得等式：12ax=3(1-a)x  解得：a=1/5。

卢精灵

恍然大悟

多谢大侠指教