请教PREP的数学题目~~

lzkisslife

 

昨天做了一套PREP 数学错了一堆 汗!!长久以来放太多精神在verbal上 唉~~现在有点急~请教的题目可能比较弱 但我真的卡住了 往NN们给指点一下 谢谢~^_^

 

 

10. In the figure above,point P (-√3,1)and Q lie on the article with centre O ,what is the value of S? (偶不会截图)

我见图上OP垂直OQ的说
 我觉得S是√3,但答案是1,很迷惑觉得很简单一道题,但怎么会和答案不同?

30. Of the 60 animals on a certain farm, 2/3 are either pigs or cows .How many of the animals are cows?

(1) The farm are more than twice as many cows as it has pigs

(2) The farm has more than 12 pigs

答案是C

我是不懂条件里的more than 什么意思 是表示大于吗?如果是这样1,2 的交集有很多种答案啊??我选的E

 32. A set of 15 different integers has a median of 25 and a range of 25. what is the greatest possible integer that could be in this set?

 32. A set of 15 different integers has a median of 25 and a range of 25. what is the greatest possible integer that could be in this set?

A 32

B 37

C 40

D 43

E 50

答案是D why??思路是什么呢?

 36. of the 1400 college teachers surveyed ,42% said that they considered engaging in research an essential goal,How many of the college teachers surveyed were women?

 36. of the 1400 college teachers surveyed ,42% said that they considered engaging in research an essential goal,How many of the college teachers surveyed were women?

 (1) In the survey, 36% of the men an 50% of women said that they considered engaging in research an essential goal

(2)  In the survey, 288  men said that they considered engaging in research an essential goal

 答案 A

 答案 A

第二个条件不也可以单独算出来吗??(1400*42%)-288 =300

 

[此贴子已经被作者于2007-10-18 13:44:40编辑过]

lzkisslife

快来人啊~~HELP!!

sydneyang

30. Of the 60 animals on a certain farm, 2/3 are either pigs or cows .How many of the animals are cows?

(1) The farm are more than twice as many cows as it has pigs

(2) The farm has more than 12 pigs

答案是C

"more than" is more than. Just kidding. Yes, 表示大于.

So there are 60*2/3=40 pigs and cows.

Statement 1 or 2 alone is clearly not sufficient.

Combine. Cows > 2*Pigs

Pigs must be > 12, so test 13. When Pigs is 13, C>2*Pigs, Cows must be 40-13=27, which is greater than 2*pigs.

When pigs is 14, cows is 40-14=26, less than 2*pigs. So cows must be 27.

crazecat123

36. 因为median是25，所以一半数字小于25而另一半大于25。 又因为range是25(最大数减最小数），所以说当最小的的数离25越紧，最大的数就越大。 
25 - (15-1) / 2 + 25 = 43
答案是 D

sydneyang

LS posted already. I am deleting mine.

[此贴子已经被作者于2007-10-18 13:34:36编辑过]

sydneyang

36. of the 1400 college teachers surveyed ,42% said that they considered engaging in research an essential goal,How many of the college teachers surveyed were women?

36%M+50%W=42%(M+W). Simplify.

And M+W=1400.

Combine the two equations. Hope it's correct.

"第二个条件不也可以单独算出来吗??(1400*42%)-288 =300 "

The question asks what number of the 1400(total) surveyed are women, not number of women who say they considered engaging, which is 300.

[此贴子已经被作者于2007-10-18 13:47:37编辑过]

lzkisslife

谢谢sydneyang和crazecat123!!

发现我把32题的greastest看成修饰possible了!!555...

lzkisslife

恩~发现自己读题的水平严重有待提高

guozili

en

[此贴子已经被作者于2007-10-19 1:54:03编辑过]