这些都是GRE数学考试中最易出错的新GRE数学难题，大家可以看看能不能对你的GRE考试有所帮助：
1.Each employee of a certain company is ineither Department X or Department Y, and there aremore than twice as many employees in Department Xas in Department Y. The average (arithmetic mean)salary
is $25,000 for the employees in Department X and is$35,000 for the employees in Department Y.Which ofthe following amounts could be the average salaryfor all of the employees in the company?Indicate allsuch amounts.
A $26,000
B $28,000
C $29,000
D $30,000
E $31,000
F $32,000
G $34,000
本题我们要注意到题目中的more than twice的字眼，我们当做twice算的时候，结果是(25000*2+35000)/3约等于28333，因为有more than，所以选的答案要么是比前面这个数大，要么小，又由于more的是X部门的，那么肯定会将平均工资给拉低了，因此，选比前面那个数小的答案，AB都可以了。。
2.Working alone at its constant rate, machine A produces k car parts in 10 minutes.Working alone at its constant rate, machine B produces k car parts in 15 minutes. How manyminutes does it take machines A and B, working simultaneously at their respective constantrates, to produce k car parts? ____________minutes
这类题目小学时候经常遇到，相信很多人都是这种感受哈
1/(1/10+1/15)=6min 1)If the dollar amount of sales at Store P was $800,000 for 2006, what was
the dollar amount of sales at that store for 2008 ?
A $727,200
B $792,000
C $800,000
D $880,000
E $968,000
直接算，800000*(1+10%)*(1-10%)=792000，即B
2)At Store T, the dollar amount of sales for 2007 was what percent of the
dollar amount of sales for 2008 ?
Give your answer to the nearest 0.1 percent.
___________%
直接算，1/(1-8%)=108.7%(约等于)
3)Which of the following statements must be true?
Indicate all such statements.
A For 2008 the dollar amount of sales at Store R was greater than that at
each of the other four stores.
B The dollar amount of sales at Store S for 2008 was 22 percent less
than that for 2006.
C The dollar amount of sales at Store R for 2008 was more than 17
percent greater than that for 2006.
本题A选项一看到就可以排除了，涉及到两个店的绝对量的比较，这个不确定，没有告诉绝对值。B选项是把两个增长的比例简单地算术相加。肯定错了。所以C肯定是对的了。。算一下也是的确是对的。。
3.A certain store sells two types of pens: one type for $2 per pen and the
other type for $3 per pen. If a customer can spend up to $25 to buy pens at
the store and there is no sales tax, what is the greatest number of pens the
customer can buy?
A 9
B 10
C 11
D 12
E 20
这个题首先就可以想到单价越便宜的我就能买的越多，因为它没有说两种笔一定要都买。
4.A list of numbers has a mean of 8 and a standard deviation of 2.5. If x is a
number in the list that is 2 standard deviations above the mean, what is the
value of x ?
x=_8+2.5*2=13_这道题不知怎么的，读题的时候度饶了，感觉很费解，什么是两个标准差，以为是个什么特殊的东西，后来问了同学才知道这就是个简单的计算题，没啥特别的，我的个汗啊，考试的时候我碰到了，我肯定错了。。
5.Frequency Distribution for List X
Number 1 2 3 5
Frequency 10 20 18 12
Frequency Distribution for List Y
Number 6 7 8 9
Frequency 24 17 10 9
List X and list Y each contain 60 numbers. Frequency distributions for each list are givenabove. The average (arithmetic mean) of the numbers in list X is 2.7, and the average of thenumbers in list Y is 7.1. List Z contains 120 numbers: the 60 numbers in list X and the 60numbers in list Y.
Quantity A Quantity B
The average of the 120numbers in list Z The median of the 120 numbers in list Z
A中，平均数肯定就是两组的平均数的和的一半，也就是(2.7+7.1)/2=4.9，因为两组的人数相同，而B中median就是(5+6)/2=5.5，所以就是B了。。
6.The figure above shows the graph of the function f in the xy-plane. What is
the value of f ( f (–1)) ? A –2
B –1
C 0
D 1
E 2
这个题就是读图题了，一重重的往外算就好了，f (–1)=2，f(2)=1，即D
7.By weight, liquid A makes up 8 percent of solution R and 18 percent of solution S. If 3grams of solution R are mixed with 7 grams of solution S, then liquid A accounts for whatpercent of the weight of the resulting solution?
A 10%
B 13%
C 15%
D 19%
E 26%
这个题小学也经常遇到，(3*8%+7+18%)/(7+3)=15%
8.Of the 700 members of a certain organization, 120 are lawyers. Two members of theorganization will be selected at random. Which of the following is closest to the probabilitythat neither of the members selected will be a lawyer?
A 0.5
B 0.6
C 0.7
D 0.8
E 0.9
这个就是组合的计算了， / =0.68(约等于)，所以选C吧，这个题可以用下那个计算器了。
9.15人中取5人，有3个不能都取，有多少种取法?
C155 –C122
10.7人比赛，A在B的前面的可能性有多少种
P77 / 2 A在B前的次数与在其后的次数相等
11.3对人分为A,B,C三组，考虑组顺和组中的人顺，有多少种分法?
P33 ×(P22 )3 先考虑组顺，再考虑人顺
12.从4个蓝球2个红球中抽两个，第二个是红色的概率：蓝红+红红=(4/6)(2/5)+(2/6)(1/5)=1/3
13.P1，P2，P3，。。。 P1=1.P(n)=24P(n-1)+8.比较P(66)/6 与4 的大小。
解法：P(n)=24P(n-1)+8化为Pn+8/23=24[P(n-1)+8/23]
令An=Pn+8/23，则化为等比数列An=24A(n-1)
14. 5*10^9square feet的shopping area换成正方形，边长是多少miles?已知1mile=5280feet
