[原创]2006年10月jj讨论稿第7篇(426--575)已更新至575题

426. Is X^2+Y odd?

1). Y=3X+5

2). Y=4X-1

A 参看354题

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427. As the figure shows, ABCD is a square and triangles DEC, DFA are equilateral. What is the measure of angle EGC?

参看285题

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428. A set contains 21 numbers, including n. If n is 4 times the average of other 20 numbers, n is what fraction of the sum of 21 numbers?

1/6  4X/（20X+4X）

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429. If the average of 7 numbers is 5, what is the median?

1). One of the numbers is 5

2). The smallest number is 5

B

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430. When x divided by 5, the remainder is 2; when y is divided by 5, the remainder is 3. What is the remainder when xy is divided by 5?

余1。（5X+2）*（5Y+3）=25XY+15X+10Y+6

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431. A box contains some red balls and blue balls. Is the number of the red balls 4 times the number of blue balls?

1). The probability of getting a red ball at random is 0.8

2). There are 40 balls in the box.

A

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432. If f and g are factors of m, which of the following must be true?

I. m/(f+g) is an integer

II. m/fg is an integer.

III. m/(f-g) is an integer

都不对。谢谢 111cara MM。

B

第2个不对

f,g是factors,但不是互质的, 比如说12的因子有6和3. 那么12/(6*3)明显不对了

B

第2个不对

f,g是factors,但不是互质的, 比如说12的因子有6和3. 那么12/(6*3)明显不对了

B

第2个不对

f,g是factors,但不是互质的, 比如说12的因子有6和3. 那么12/(6*3)明显不对了

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433. Of the 16 numbers in a set, each is either multiple of 5, or even, or both. If 8 numbers are multiple of 5, 12 numbers are even, how many numbers are divisible by 10?

4

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434. If you enter ABCDEFG, DABCGEF will be out put; then DABCGEF, CDABFGE will be output? After at least how many enters, ABCDEFG will appear again?

Answer:

ABCD will appear after every 4 enters, EFG will appear after every 3 enters.

The least common multiple of 3 and 4 is 12, therefore, at least 12 enters are required.

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435.一个building lot是quadrilateral，要围绕这个lot加fence，
  问fence的长度是否大于某个给定的数？
1）building lot的面积给出
   

2）building lot四个边长的average mean给出

B

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436.就是那题不规则的图形（三角形＋梯形）求面积的... AB=BC=8, CD=2, B和C都是直角, AE=ED=13。

参看以前JJ

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437.一个四位数，说是一个满足条件的最小的正整数，4个数字的乘积为450，问百位上的数是多少？
是个DS题，两个条件好像就是说被某数除，余数是多少。

450=2*5*5*9

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438.一组连续的正整数，最小的是3，问有几个数？

（1）the average mean is 6 ;
（2）the range = average mean

D 

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439.91-93年的average salary是A元(一个数字，忘记了)，公司的target是未来3年每年的平均工次升幅是x%，问96年的平均工资是多少？
  是这个题目的变体，方法一样，题目换个说法。

A (1+X%)³

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440.15n divided by 6, what remains,
1）n can divided by 2
2）n can divided by 3

A

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441.给你三个不等式，描述了M+N、N+P、M+P的区间，问M+N+P的范围。

没有具体数值不好算

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442.就是输ABCDEFG,出来DABCGEF，每一次都按这个规律输出，问多少次能第一次变回ABCDEFG

12

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443.给出39200立方毫米，问多少立方厘米。
  连换算公式也给出来了。唉

39.2

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444.还有就是两条平行线，一条上4个点，一条上5个点，9个点能连成多少个三角形。

C₄¹*C₅²+C₄²*C₅¹

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445.Peter的家在一所学校的正东面的A米处，Mike的家在这所学校正南面的B米处，Lily的家在Peter家的正北面的C米处。问lily家距离mike家的直线距离。这题是很容易，但是后来发现我把Mike正南看错成正北来算了。可想而知。。。。。

新题(我觉得是的):B+C

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446.DS: a,r,c,m all positive int, a^r > c^m?

1) ac^-1>1 & a^r > a^m
   

2) a^rc^-m >1

D

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447.DS: A software retail store purchases 100 games at $30 each. Then n copies were sold at $50 each, and the rest were sold at $x each. The store made a profit of 1500. Is x less than 40?

1) n > 6

2) n < 8

B   50n+(100-n)*x=4500，代入数值检验

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448.DS: 12 movie screenings, each screening sold at least 90 tickets. Is the average number of tickets > 100?

1) more than half of the screenings sold at least 110 tickets.

2) 3 screenings sold at least 120 tickets.

A．  不选B因为可能等于100

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449.DS: In a company with E employees, m of them are male, n out of m are the males that have served the company for over 5 years. What is the percentage of the male employees that have been serving for over 5 years within the company?

1) if an employee is picked at random from the company, the chance of the employee be male is 0.2

2) the chance of picking an employee who has served for over 5 years from the male employees is 0.8.

C

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450.DS: M & N both 3-digit number, M > N?

1) unit-digit of M is smaller than unit-digit of N

2) hundred-digit of M + unit-digit of M > hundred-digit of N + unit-digit of N

C

451.PS: Triangle ABC, place a point E on BC so that ACE is equilaterial & BE=12. The area ACE is 9√3. What is the area of ABE?

18√3。先求出等边三角形的高，和ABE是共用一个高的，底是BE，面积就可以求了

1/2*3√3*12=18√3

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452.PS: (79/161)*(√22-
  √18)² is closest to? 0,2,4,6,8

A

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453.PS: The number of employees of a particular department constitutes for 22% of the total number of employees in the company. If the company reruites 2 new employees for every employee in the department ( 他没有说新增加的人会不会加到 department 里面，但肯定是会，因为选项没有小于22%的), what is the new percentage of the number of employees in the department compare to the whole company? 40%,44%,46%...

选46%。 X=22%Y   (X+2X)/(Y+2X)=(3*22%Y)/(Y+2*22%Y)=45.8%

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454.PS: a₁=1, a_n+1=1+(1/a_n), a₅?

Answer:8/5.  1, 2, 3/2, 5/3, 8/5

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PS
此主题相关图片如下：

[attachimg]51608[/attachimg]

BC=8, AB=6, DE=30, AE=?
answer: 60

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JJ2 需要澄清一下
  就是有 Business Degree & 会讲 French 的那题，他最后的问题很 tricky, 他是问 what is the percentage of the people with business degree that can speak French? 他是在问有 Business degree 里面的人有百分之几会讲 French, 所以答案是 50%.

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JJ78 变形: (@a)^2 * @b = even or old?

1) a even

2) b odd

A

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JJ132 变形: 定义不变 I.X#Y=Y#X II.X#0=0 III.X#1=X^2+1 问哪几个成立。

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JJ250  应该是选C 因为平行的 tangent 应该处碰圆的两点的距离就是直径，也许有人说如果两条线可以重迭，但是依我看来重迭的线不算在平行内。

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455.PS X>-1, 1/x²+1/X^-4 = 0, the value of x is between

a. -1 - 0, b. 0-1, c. 1-2, d. 2-3, e. 3-4

感觉题目有问题。

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456.ps有个 seashell图形
  问最长边?

原作者：我没软件可画图，就是最底是一个等腰三角形边长各为1cm，算出斜边是根号2，再以根号2为一边,1cm为另一边再求出另ㄧ个直角三角形的斜边，依此类推(最外围的那个边都是一公分)！喝喝
  会不会很难懂
  不过最长那个边算出来是根号13 然后答案没这个要选3.6 ^^

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457.ds也是图形题,问最大那个长方形的面积?
(1)y=24 (2)x=18

答案是D都可以算出来。参看以前JJ

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458.ps -16≤ x ≤ -9 , 4≤y≤ 8(这个好像是8不确定) 求
  根号-xy 可以是下列哪个值?
(a) 2, (b)6 (c)32

B

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459.ps f(x)= 7-x when 0≤x≤4 or  f(x)= x/2-2 when 4<x≤6 问 f(x)的值在下列哪个内?
0<f(x) ≤1 and 3≤f(x) ≤7

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460.k是5的倍数, k被6除余几?
1)k被4除余 3
2)k被12除余3
CHOOSE:B

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461.

      a            b   c  
  ---●-|-----|-●---●-|-----|-      问哪个倒数的值最大?

      -2     -1           0    

A

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462.DS，P=300+0.2165n，p是某产品价格，n是当月销售数量，问当月revenue? (数字全是我乱设的，反正数字不重要，p跟n才重要)
1). n=9000
2). 提供p的数字
CHOOSE

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463.(转贴他人的)还有一个DS似乎以前JJ没见到，就是说500个东东，每个长度都不一样长，其长度小于153的有76%，问其median是否小于100？
（1）在大于100的那些里有60%大于153
（2）在大于100的那些里有40%小于153
我选d

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464.
  有个车子要开
   1KM的路程 ,用R km/h的速率,如果改用r+20 km/h的速率少用4秒
  问r=?

1/r=1/(r+20)+4/3600

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465. If x and y are integers, |x|*|y|=?
1). xy=10
2). x*|y|=-10

D

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466.两个圆相切，两圆上各有一点p和q，问这两点的距离最远是多少
1.知道两个圆的半径之和；
2.知道两个圆的半径分别是多少。

D

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467.定义＃为X#Y=(X+Y)^2－2XY，问下面三个式子哪些正确：
1.X#Y=Y#X   2.X#0=0,  3.X#1=X^2+1,  选项是1成立;1,2成立;1,3成立等
选1 ,3成立

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468.还有一题说有369人参加投票，分别有支持跟反对的，支持好像是255个人，反对是114吧,其中有一些原本反对的人被拉去支持那边，问至少要有2/3支持的人，那这些原本反对的人要被拉几个人到支持那边！

9个.  255-369/3

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469.还有一题是今年投资30265圆(数字不确定
  不过不影响) 每一年可
增加4% 问三年后的钱?
30265 *(1.04)^3

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470.
  罗马题，问以下=a? 列有(1)｜a^2｜/a (2)(｜a｜/a)*a (3)..

原作者：不记得了，反正就是绝对值的符号和2次方，想着法儿划就是了
   

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471.y=x^n+1 问x? DS （1）y=1 (2)n是odd

A

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472.以p、o为圆心两个圆，相切，x、y在圆上，问xy的最大距离？DS （1）告诉PO距离
  （2）两个的半径
  。。。。最简单的一道了

D

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473.dinner有鸡肉、牛肉、鱼构成，说鱼至少5份
是条DS …??sorry想不全了，急得不难，就是列出公式，代入两个条件看是否能求解

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474.
  有一个长方体，长宽高分别是XXX(有数，但我忘了！）inch, 外面套一个塑料垫子，垫子高1inch, what is the volume of the xx(一个生词，好像是bome,poom之类的！）
   

参看以前JJ。

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475.A club has 10-40members. Sometime, the members sit on tables with 3 of them sit on one table, and 4 members each sit on the others. Sometimes the members sit on tables with 3of them sit on one table and 5 of them each sit on the others. When there are 6 members each sit on the other tables, what is the number of the members sit on one table?(题目好像是这么说的，这道题我不会做）答案好像有2，3，4，5，6。

题目好像有问题

476.跟前面的机经类似，问1/101+1/102+...+1/150 的范围，

1/3-1/2

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477.N is a common multiple of 75, 98,140, which of the following is true?

(i) N can be divided by 9, (ii)N can be divided by 49, (iii) N>14000

B C

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478.268的20次方的个位数？
   

6

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479.X除以3余1，除以5余1，但X+Y除以3和5都正好，问最小的Y是几？

   选项：2，4，14，  ， 30

我选C 解释在13楼

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480.3种作料：SUGAR，CINIMON，CLOVE 共计41OUNCE，问CI有多少OUNCE？

1 SUGAR：CI=5：3

2 CI：CL=3：4

C

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481.（1/（4-根号15））的平方=？

1/（31-8√15）

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482.有道题目，我不会画。一个象  Y的的三叉路口(3条都不是一条线,而是三条路)，三条道路的两边都是平行的

，而且路宽相等。最左边的小锐角是T，右上钝角是R，左下钝角是S，求T=？(哪位高手帮加个图?)

1 R=140   2 S=120，（或者，R=120，S=140）

100．不敢确定，因为题目说T是锐角

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483.(原135). c*m=n*q,都是integer,问c是否是q的multiple
1)m是质数
2)n是m的multiple
讨论：C，n和m可以是0
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484、99到301中所有偶数的和

参看以前JJ

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485、0.abc那道

题目不全

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486、两个圆外切，两个点分别在这两个圆上，问最远距离
  （1）圆心距10 （2）两个圆的半径分别为3和7

D         

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487、q<s<t? (1)t-q=/t-s/+/s-q/ (2)忘了

作者：总之选a

2)a+c>15

D

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489.一个选举,只要通过2/3, 就可以当选了.大概是有396个人投票,其中支持的有254, 反对的有142, 问从反对的人中换多少个人到支持的人，就可以当选了.

10。 396*2/3-254=10

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490.一个数列,从第一项开始,之后每一项为1/n(n+1), 求第100项之前的合.这题我不太确认的.记得是选了99/100,还有一个选项是100/101,我觉得是这个我做错了,本来是想拿满分的.

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491. grocery store sells some mixture of 1.5 kg cashew nuts and other kind of nuts 6kg.  for $ 1.5 of every 0.25kg.  And then it tells you that the sales is more than 50% of the total cost. The cost of cashew nuts equals to the other kind of nuts.. So what is the cost of cashew per kg..
参看381题。10大洋。设巴西豆的单价是X， (1+50%)*（1.5*4X+6X）=1.5/0.25*(1.5+6)  X=2.5  故XX的单价是4*X=10

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492. (202). If A=0.abc, where a, b, and c are digits of A, is A greater than 2/3?
1). a+b>14
2). a+c>15
大家注意，原JJ有误，原题2里应该是 a+c 不是B+C，
    今天考的时候，差点错了。

D

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493. a rectangle 交一个圆在(4,0), 和（－4，0），问maximum radius是多少。
     

无限大

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494. 有个平行的交叉路口，（不会画图，）大致就是三叉路口，知道两个角，求另一个求 DS

~~~

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495. 7个PROFESSOR给他学生分配项目那题

原作者：答案应该是210。。
    

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496.还有开始一道很奇怪的题，算STANDARD DIVEATION。好像是说一个COMMITEE,一个有6个member,3j, 3k, 还有一个committee,4 people, 1j, 3k. DS,问关于第二个COMMITTEE标差的。
     
1）好像是说第一个COMMITTEE的标差为0
2）J=K   KEY D。

原作者：两个算出来都可以。

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497.（俺不会画图，大家想象吧，很简单的）一个半圆的直径在X轴上，处于第一、第二象限，直径的左端点的坐标（m,0），右端点的坐标(k,0)，问半圆的面积：m是个负数，k是一个正数，半圆面积
     

派(k-m)^2/8

498．If the perimeter of a square is k/16, then the length of a side of the square is? 这道题出现在第30几题，我盯着屏幕盯了两分钟，一直在问自己：是直接除以4吗？呵呵

K/64

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499.一个教授老先生，有7个PROJECT，分给他老人家的A,B,C三个学生，A分两个，B分3个，C分两个，问多少种分法？

答案是210 。
            C₇²C₅²

之前看了有些讨论贴，说答案是630，但是我考试时，210已经是5个选项中最大的数字了，没有630这个选项，也就是直接用C₇²C₅²计算就可以了，不用乘以3。

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500.x+y除5余1,x+z除5余2,除5余3,问x+y+z初5余几?
这道题，选项是0  1  2  3  4

余3。

原作者：我当时选了3，本来看之前的JJ，有人说答案是1，但是考试时我不放心，拿了3个数来算，后来算到是3……

我是设x、y、z分别等于5、6、7，大家看看

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501.一个分段函数

f（x）=7-x     当4≤x≤7，

f（x）= X/2+1  0≤x<2

问你f（x）的取值范围。（数字可能有出入）

[0，3]

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502.一个等腰三角形，一个角等于120度，给了一条腰的长度，问你面积（又是简单题，注意词汇就好，我当时就是不懂那个词，猜的，因为三角形这样让你求面积，显然是特殊的三角形啊~~）

一腰*一腰*sin60°

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503.一个直角三角形，斜边等于X+2，两直角边分别等于X-2、X，求面积。选项是纯数字，所以先要求出X。

8 。 X²+（X-2）²=（X+2）²  X²-4X=4X   X=8

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504.一个公司，最后7天做成了10笔业务，其中3天每天只做了一笔，问你最少那天做了多少笔？（大概是这样）

好像是以前JJ。

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505.比较大小
            

根号下10 

三次根号下100 

四次根号下10000  

五次根号下10000

六次根号下100000

不难，就是换成同底的幂来比较，选C

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506.DS；if x is even, then (x)=x+1, if x  is odd, then (x)=x-1, is a²b even?

1.a is even

2.b is odd

这是数学部分最后一题，只剩几十秒，随便选了C。同意
            

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507. the unit digit of 7^468 is

7^(4*117)=2401^117, so I chose 1

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508. PS 两个三角形,都告诉你直角边的长,问斜边差,很简单!!!

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509.PS 我的最后一道题,实在没时间了,就猜了一个答案,但其实很简单,给你一个经济模型的公式,其实是数列,告诉你A0=0, A1=1,问A3=?

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510.DS 具体题目记不清了,告诉你3样东西总和,还有它们之间的比例, 问其中一样的具体数量
            

(1) 这样和其它两样和的差
            (充分)

(2) 这样和另一样的关系
            (不充分,因为没有给出和第3样的关系)

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511.PS X>-1, 1/x^2+1/(X^-4) = 0, the value of x is between

a. -1 - 0, b. 0-1, c. 1-2, d. 2-3, e. 3-4

我感觉这个题不对啊

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512.X+y=10,那1/x+1/y=?
10/xy

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513.Ａn=A_n-2+11(注：n-2表示n位数的前两位），如果Ａ_１＝３９，Ａ_２＝４３，问６３３是否在这个数列里，（Ａ１，Ａ３的具体数不太确定，但是是这样一道题）

在。（633-39）/11=54

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514.一个E event的发生概率是K,那它不发生的概率是多少
答案 1-k

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515. 一个数列，后项是前几项相加之和，比如a2=a1,a3=a1+a2,已知n>=3,an=p,问a(n+2)等于多少？

以前JJ里有这道题，答案4P
an=a1+a2+...+an-1=p，an+1=a1+a2+...+an=2p，
            
an+2=a1+a2+...+an+1=2p+2p=4p
补充一下，a1=t, 问题是what is the third after t?

4t

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516. Solution A contains 10% salt and solution B contains 15% salt. If 200 units of A and 300 units of B are mixed, the resulting solution will contain what percent of salt?
答案13%。（10%*200+15%*300）/500=13%

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517. If x and y are integers, |x|*|y|=?
1). xy=10
2). x*|y|=-10

D

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518. What is the remainder when 7^468 is divided by 10?
类似题好象是7381        具体数字可能有些不同，但原理都一样

余1。

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519.  @k represents k-1(k is odd)， (check out past jj) k+1 (k is even)  ask @a2@b even or odd? 
1). a is odd
2). b is odd
C 除去0的情况

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520. JJ202. If A=0.abc, where a, b, and c are digits of A, is A greater than 2/3?
1). a+b>14
2). b+c>15

D

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521.应该是一个新的DS，一个学校学生either speak French or Spain,问会说法语比占的学生比例
1)    10(反正给的是一个数字)
2)    会是S是F的两倍
实在是记不全了，反正应该选B

522．一个club,有时每桌3人，剩一桌坐4，有时坐4桌，剩一桌坐5，那坐6个人，剩几？
应该还有其它条件，记不清了，考点是3m+4=4n+5=6k+? 求通项的

举例，25，除6剩1。

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523. DS: r≠0, what is the value of s?
a. s-9=r-9
b. s2=4

E

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524.ABCDEFG序列转换。首先是BCDAGEF，问多少次转换后回到最先状态? 12

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525. x, y ≠0, what is y/x?

a. 2y-3q=20

b. y2=q2

E

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526.有一个dealer以manufacture price买了一个东西，然后以20% discount off its retail price of $440卖掉了，dealer的利润是10%manufactur price，问manufactur price. 

(440*0.9/1.1)

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527.金字塔那个，问
  哪一行出连续出1/2, 6/11, 5/9.

 (7)

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528.求一个半圆的面积的题目，很简单。
  （抱歉，不知道怎么画图上来，半圆的两端在x轴上，(m,0), (k,0).

 pi * (m-k)^2/8

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529.(data sufficiency) xy^3<0?    (1) xy^3 <0; (2) x^2y<0 

 (A)

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530.有一道关于鸟类迁移的题目：在被观察的鸟群中，30%是male，在migration的鸟中，20%male, 问 male 和 female 的migration rate的比率。 migration rate = number of birds that migrate / number of total birds

(20%/30%) / (80%/70%)

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531.有一群人做桌子，说得比较绕，大概意思是：总人数大于10小于40（1）5个5个一桌坐，会余3个人做一个桌子，（2）4个4个坐的话呢，会余3个人。问6各6个坐，会有一个桌子人数少于6，那么这个桌子有几个人 

（5，一共有23个人）

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532.(data sufficiency)30个人要学prerequisite accounting course，问有多少人两个都学。
   

条件：（1）20个人要学prerequisite financial cours； (2) a total of 40 students who study P.A.C. or P.F.C. or both 

(C)

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533.1998年Jean的salary比XXX多，1999和2000年，每年中他们的salary都长了3%。问2000年他们工资的difference长了多少。   

1.03*1.03-1

534.（data sufficiency) 求一个isoceles的周长。
    条件：
    （1）一个角是120度
    （2）面积是多少 

（C）

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535.Is  r/s a 无限循环小数（我不认识这个词啊，猜的)
1)1/r is  无限循环小数
2)1/s is   无限循环小数
My answer is E

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536.per hour x miles, how long will take  y yards(1mile=1xxx yards)
1)x=y

2)y=10
My answer is A

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537.la^2l/a=?
I  a
II  lal
III a^2/a
1)I only
2)IIonly
3)I and III
My answer is 3

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538.根号下x+y=
1)根号下x  +根号下y = 5 
2) 根号下xy = 7
My answer is C

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5) the cost of 20% of product in the company is d, the rest is d/2, what is the percentage of the rest of product to the whole cost of the company?
My answer is 2/3

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539. K是三位數，個位數是nonzero，求K的十位數：
     

條件一：K+9的十位數是3

條件二：K+4的十位數是3

Answer: A (條件一：因為個位數非0，所以加上9一定進位，故K的十位數是2。條件二：不能確定十位數是2 or 3

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540. N是the first six 連續數的總和 greater than t ，S是 the first six 連續的總和greater than t+6，問以N表示S?

這題我其實看不大懂耶，搞了半天選了A. N+6

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541. M contains all the prime factors of 770. N is a prime factor of M but is not a prime factor of 770. What is the least possible value of N?

3

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542. A set contains 12 integers, is the sum of all integers less than -4?

1）The 12 numbers are consecutive.

2). The number of negative integers is greater than the number of positive integers.

C

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544. Mixture B is mixed with 1.5kg of C and 6kg of D and sold at price of $1.5/0.25kg. In the mixture, C and D have the same value, what is the unit price of C?

参看以前JJ

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545. The segment between (k,0) and (m,0) is the diameter of a semi-circle. What is the area of the semi-circle?

Pi(m-K)²/8

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546. Is n(x-y)<0 ?

1). n² >0

2). x-y <0

E

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547. If k>8, k=?

1). K is an odd number less than 12

2). K is a prime number less than 12

B

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548. At speed of r mile/hour, bob can run 1 mile in t minutes. If Bob ran at speed of 20+r, it would take t-4 minutes to run 1 mile. r=?

R*t=1=(20+r)*(t-4)

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549. Is 4< 3m < 6?

1). m<-1

2). m> -2

A

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550. If k is a multiple of 5, what is the remainder when k is divided by 6?

1). When k is divided by 4, the remainder is 3

2). When k is divided by 12, the remainder is 3

E

551. Is two circles tangent to each other?

1). The distance between two origins is equal to the sum of their radius.

2). Two circles have less than 2 intersections.

A

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552. S^4t^3r^5>0, str>0?

1). t>0

2). r>0

E．  S可能小于0

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553. The sides of a right triangle are x+2, x, and x-2, respectively. What is the area of the triangle?

24

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554. If Jack had earned 1.5 percent more in annual interest on an investment, the interest for one year would have been $45 greater. How much did he invest at the beginning of the year?

45/1.5%=3000

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555. If the perimeter of a square is k/8, what is the side length?

K/32

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556. A 48 kg of mixture is consists of A, B, and C. How much B does it contain?

1). A:B=5:3

2). B:C=3:4

C

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557. If N is a common multiple of 75, 98, and 140, which of the following must be true?

I. N is divisible by 9

II. N is divisible by 49

III. N is greater than 14000

参看以前JJ

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558. In a certain conference, a new plan is to be voted by 369 represents. At the first vote, 255 approve the plan and 114 object the plan. If the plan needs at least 2/3 of the represents? support, to vote the plan, how many objectors should change to approve the plan?[The numbers seem inaccurate]

255-369*2/3=9

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559. A video dealer purchased video at manufacture price. During a sales promotion, he sold the video for 20% discount off its retail price of $440. If he gained a profit of 10% of the manufacture price, what is the manufacture price?

440*80%/1.1

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560. Is xy^3<0?

1). xy^3 <0

2). x^2y<0

A

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561. Integer N is greater than 10 and less than 40. What is the remainder when N is divided by 6?

1). When N is divided by 5, the remainder is 3

2). When N is divided by 4, the remainder is 3

余5。这个数是23

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562. 1. Is m/n an infinite recurring decimal?

1). 1/m is an infinite recurring decimal

2). 1/n is an infinite recurring decimal

E  已改正

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563. When integer x is divided by 3, the remainder is 1; when x is divided by 5, the remainder is 1. If x+y is divisible by 3 and 5, which of the following is the least value of y?

2, 4, 6, 14, 30

选14。

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564. Which of the following has the smallest value?

A. 10^1/2

B. 100^1/3

C. 10000^1/4

D. 10000^1/5

E. 100000^1/6

C

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565. Someone is running at x miles per hour. How long time will take him to finish a y yard distance?

1). x=y

2). y=10

A

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566. If x is nonzero, |x^2|/x=?

I. x

II. |x|

III. x^2/x

I， III

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567. (x+y)^1/2=?

1). x^1/2+y^1/2=5

2). (xy)^1/2=7

C

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568. Company X produced a batch of tools. 20% of the tools cost p each and each of the other 80% cost p/2. The cost on the cheap tools is what percent of the whole cost?

（80%*P/2）/（20%P+80%*P/2）

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569. If y=x^n+1, x=?

1). y=1

2). n is odd

A

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570. When 0<=x<=4, f(x)=7-4; when 4<x<=6, f(x)=x/2-2. What is the range of f(x)?

Reference answer: 0<f(x) <=1 and 3<=f(x) <=7

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571. Someone built fence surrounding his quadrilateral garden. Is the length of the fence greater than 200?

1). The area of the garden is 1600

2). The average of four sides of the garden is 45.

B

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572. A ship travels 8km due north then 12km due east and then 8km due north. What is the distance between the initial point and the destination?

20

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573. N is an integer. If N! ends in exactly 3 zeros, what is the smallest value that N can have?

15

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