gre数学题及解析!在
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。。
以上是小编为大家带来的gre数学题及解析内容，希望大家认真练习，及时核对答案解析资料。