[1006G]xiaoyaozi5566的GRE数学解题站

xueyiUID: 2647060

23、这个表是一个收费表，就是如果你要$1000的话就要1块钱办理费，$500的话就要2块钱办理费，而现在的问题是怎么样取1500而交最少的办理费。2 E3 I) T* {  Z
不过这样看来的话好像A,D,E都是3块钱，额，看来我理解有错误，有人知道么？帮忙解答一下！; A4

这个表的纵轴不是具体数额，而是百分比哦：）

尾羽UID: 2482591

1.in an election each voter voted for one of two candidates, X and Y. The number of votes that Candidate X recieved was 1/3 more than the number of votes that Candidate Y received.

the fraction of the total
vote that Candidate X n            4/7
received
答案C，这题应该怎么算？三分之一是X的三分之一还是Y的？

2.the measure of two angles of a parallelogram differ by 52 degree. The number of degrees in the smaller angle is
答案 64，关键是这个“differ by 52 degree”怎么理解？

3.The electricity used by the water heater was measured separately and its cost per kilowatt-hour was one-half the cost per kilowatt-hour of the rest of the electricity used. The cost of the electricity used by the water heater was most nearly what fraction of the total cost of all the electricity used?

答案1/9

解答：
1、是说X比Y多1/3，也就是X=4/3 Y，而X+Y=1（选票总体为1），这两个方程就能解出来啦
2、那句话的意思是相差52度，前面解答过这题，在第二页
3、前面解答过，请你到前面翻翻吧
by xiaoyaozi

loveromeoUID: 2603347

太好了太好了:loveliness:
请问黄皮书Section 64
第22题：If a pie graph (such as the one above)were drawn to scale to represent the budges distribution into the five categories, what would be the measure of the central angle of the sector representing savings?
答案是(E)54%  ，我选的是(A)15%

第25题：If all of the emergency assistance funds in 1993 were distributed among 40 groups, which of the following is closest to the average(arithmetic mean) amount distributed per group?
答案是：(E)$14，000

第27题：The measures of two angles of a parallelogram differ by 52 degrees. The number of degrees in the smaller angle is     答案为(E)128    这题是凭感觉做的，题目读不太懂

小弟巨怕数学，请大侠指点:mad:

解答：
前面两题有图的吧？我没黄皮书了
27、这题说的是，平行四边形的两个角相差52度，也就是，大角-小角=52，然后，又因为平行四边形大角+小角=180$ \$ n/ S/ `9 K7 \* k2 `& _  z
so，两个方程相减，得小角=（180-52）/2=64，你的答案错了
by xiaoyaozi

susuyaaUID: 2324593

哈~我又厚脸皮来发问了.谢谢楼主不厌其烦的解答,如果有其他路过的好心人刚好会也麻烦帮忙解一下以减轻楼主麻烦~感谢!!
9610(4)

24. If those employees who made 6 or more errors were removed from the sample and an employee were selected at random from those remaining, what is the probability that the employee selected made no errors?

(A) 1/11

(B) 1/22

(C) 1/39

(D) 1/50

(E) 1/78

26. In the rectangular coordinate system above, if P, not shown, is a point on AB and if the x-coordinate of P is 1, what is the y-coordinate of P?

(A)4/3

(B)3/2

(C)7/3

(D)5/2

(E)8/3

After a store had sold k television sets for p dollars each, it reduced the price p of each set by 5 percent and then sold twice as many sets at this reduced price.

11.

The total revenue from the sale of all of these television sets

2.95pk

Ans: B

解答：

24、这题说的是把犯六个以上错误的去除掉之后，随机选一个人，那么这个人是不犯错误的员工的概率。除掉之后，就剩78%了，而不犯错误的人占2%，因此概率就是2/78=1/39，选C

26、虽然没有给出图，但大概知道是求一条直线上一个点的问题。直线的方程式y=ax+b，根据AB两点可以求出方程中的a和b，求出来之后再把P点的x坐标带入，就能求y坐标了

11、前面收入是pk，后面价钱降为0.95p了，而售出了2k台，后面的收入就是1.9pk，加起来就是2.9pk，so，右边大

by xiaoyaozi

susuyaaUID: 2324593

25. If the tax per gallon of gasoline in Canada were doubled and the increase in tax added to the price per gallon of gasoline, what percent of the resulting price per gallon would the tax then be? (不明白这句是什么意思?)

(A) 36%

(B) 50%

(C) 64%

(D) 75%

(E) 90%

26. A gardener wishes to plant 5 bushes in a straight row. Each bush has flowers of a different solid color (white, yellow, pink red, and purple). How many ways can the bushes be arranged so that the middle bush is the one with red flowers?

(A)24

(B)30

(C)60

(D)96

(E)120

29. A candy assortment consists of seven flavors of chocolate-covered creams packed in two-layered boxes with 27 creams in each layer. The flavors are always packed in rows so that the flavor varies with each piece in the following order, vanilla, orange, cherry, vanilla, raspberry, lime, pecan, cherry, lemon. How many chocolate-covered vanilla creams are needed to pack 200 boxes of the assortment?

(A)600

(B) 1,200

(C) 1,800

(D) 2,400

(E) 3,600

解答：

25、那句话的意思是，税收占价钱的百分比是多少，本来油价1.7，税收0.8；double之后油价2.5，税收1.6，因此占的比例就是1.6/2.5=46%

26、就是一个排列组合题，中间一个定好了是红色，然后其他的就是A4 4了，你也可以这么想，红色确定之后，白色有四种选择，然后黄色油三种选择，然后粉色两种，然后紫色一种，就是4*3*2*1=24

29、那种排列共9个，其中有两个vanilla，一层27个，就有6个vanilla，两层12个vanilla。200盒就是200*12=2400个vanilla，选D

by xiaoyaozi

susuyaaUID: 2324593

以下是我觉得答案可能有问题的题目~


6.

Area of square region Ⅰ Area of square region II

0.004

Ans: C,  我选A??

12.

The degree measure of ∠DBC

Half the degree measure of ∠BDC

Ans: B,  我选C??

谢谢解答,十分感激!!

解答：
12题是等边三角形，所以答案是B
by xiaoyaozi

bona_renesasUID: 2599385

第24题，说的是热水器的电的价格是其他的用电的价格的一半，因此，我们假设一共用了100度电，每度电1块钱（热水用电每度电5毛钱），那么热水用了20度电，就是10块，然后总共是90块，因此热水器用的电的cost占的比例为1/9，选B3 l. x3 Y  B# Y! U* O; M& F
susuyaa 发表于 2009-10-9 10:28 [/quote]

这个题的解答，前两句我都看懂了，可是红色的部分“那么热水用了20度电”，这哪里冒出来的？不懂不懂。。。
逍遥子赶紧给解释下吧，抓狂了，答案我都看不懂了。。。。

甭解释了。。。我明白了，硕大一个图标我竟然忽视了。。。
谨以这帖子提醒各位一定不要犯晕。。。

xiaoyaozi5566UID: 2510336

38# bona_renesas
那个圆饼图不是water heater占20%么？我假设用了100度电，那么water heater就20度了

xiaoyaozi5566UID: 2510336

回susuyaa，今天得预习一个实验，我明天来给你解答，不好意思啊

zyp8756UID: 2594775

谢谢答疑 第二题错的太弱了 25# xiaoyaozi5566

银落UID: 2632560

To obtain an FHA mortgage for $50,000 or more, the home buyer must have a down payment equal to 4 percent of the first $25,000 of the mortgage amount and 5 percent of the portion in excess of $25,000. At settlement the buyer pay a mortgage insurance premium equal to 3 percent of the mortgage amount. What is the maximum FHA mortgage, if any a buyer can obtain if the buyer has only $6,000 available for the down payment and insurance premium?
(A)  $62,500
(B)  $71,875
(C)  $78,125
(D)  $125,00
(E) The home buyer cannot obtain an FHA mortgage

解答：
这题说的是，前面50，000需要付25,000*4%+25,000*5%=2,250.然后剩下6,000-2,250=3,750，这部分是支付总费用的3%的，3750/3%=125,000
D应该少了个0吧？
本题应该选C：
（x-25000)*5%+3%x=6000-1000，我看错了，感谢pipiloveu同学~
by xiaoyaozi

rachel4890UID: 2368107

模考第五套 section 3 T28

It the average (arithmetic mean) of x, y, z,5, and 7 is 8, which of the following must be true?

I The median of the five numbers cannot be 5

II At least one of x, y and z is greater than 9

III The range of the five numbers is 2 or more

(A) I only

(B) II only

(C) III only

(D) I andIII

(E) II andIII

不明白第三个，我可以推出第二个是正确的，但第三个的range 至少也是9-5=4啊，那不就应该是4 or more吗？

谢谢楼主

解答：

2 or more是不是包含了4 or more呢？:)

by xiaoyaozi

benbenqiaoUID: 2585180

43# rachel4890
一个数大于4，那么它必然大于2，所以III也是正确的

susuyaaUID: 2324593

(9704)   ~谢谢!!

P,Q and R are distinct points on a straight line, with Q between P and R, S is a point not on the line, and QR = QS

13.

PR

PS

Ans: A

16. Diane completed each of her exercise sets in 75 seconds and rested for 55 seconds between the exercise sets. What is the ratio of the amount of time it took her to complete an exercise set to the amount of time she rested between the sets?

(A)5:6

(B)5:11

(C)6:11

(D)11:5

(E)11:6

30. Which of the following CANNOT be a factor of 2^iand 3^j, where i and j are positive integers?

(A)6

(B)8

(C)27

(D)42

(E)54

                                     x is an integer greater than 500
4.

The value of the integer formed if the order of the digits in x is reversed

200

Ans: D

解答：
1、PR=PQ+QR=PQ+QS，根据三角形两边之和大于第三边，可知PR>PS
2、我想each表达的是3个，所以每一个set用时75/3=25，因此25：55=5：11（either指两个，every指三个以上）
3、就是说，选项中哪个的分解中包含除2和3以外的因子，42=2*3*7，有个7，所以选42
4、左边说的是把x的数字倒过来的结果，如果x是521，那倒过来就是125，比200小；如果x是522的话，倒过来就是225，比200大；
因此答案是不确定
by xiaoyaozi

susuyaaUID: 2324593

(9604) 抱歉阿逍遥子~我好多疑问阿!!!


A grocer buys apples at the regular price of 38 cents per pound.
8.

The amount saved by the grocer on a pur- chase of 100 pounds of apples if the price per pound is x cents less than the regular price

The additional amount The additional amount purchase of 100 pounds of apples if the price per pound is x cents more han the regular price

Ans:C, (看不懂题目??)


O is the center of both circles.

12.

The area of the circular region with radius OP

The area of the shaded sector ROQ

Ans:C, (疑问:为什么不是D? OP和OQ比例长度皆没说明阿!?)

p, q, r, and s are the coordinates of the points indicated on the number line.

14.

p+q

r+s

Ans:B, (疑问:为什么不是D? 不知O点在哪吧!?)

解答：
8、左边是说降价x的话买100磅省了多少钱，右边是说提价x的话买100磅亏了多少钱，显然相等
12、偶觉得也无法确定...
14、数轴是右边大左边小的
by xiaoyaozi