******2003-1-05******
***03JAN03 math, 1/3 Math JJ Robert之家 发表于 2003-1-5 19:27:41
Math is not difficult, but got a suck score at verbal. sigh.......anyway, here are some JJ today. Hope can help others.
58. Is X<0?
a.) X^3<0
b.) X^2+X+1=0
[确认]A
59. root^4 [(X-3)^4] + root[-x│X│]=?
[讨论]X<=0才能有解。
60. A can finish job at X hours, B takes twice the time A need, ask how much hours to finish the job with A & B work together. One old jj.
[确认]1/(1/X+1/2X)=2/3X
61. Which one equal to 5000? => d.) 3/0.0006
[确认] 3/0.0006
62. One person running around a circle, after 300 feet return to the start point, ask how much is the radius?
I.) 150/Pai
II.) 60/Pai
III.) 25/Pai
=>I. III
[讨论] I. III。是否告诉跑几圈。
三个圆是tangent to each other, and circumferences touch each other's . Not Circunference going through each other's center.
怪不得我左看右看上下看就是看不出也找不到等边三角形内那有3个扇形.
21.
6个东东,取四个,without replacement, 问有多少种combinations? ans: c(4,6)=15
应该是P(4.6)
35.调查某网站受欢迎的程度,共有400人接受调查。其中说网站内容好的有185人,说网站速度快的有270人,问两种都没有说的。 D
(1)两者都说的有25人
(2)只说内容好的有160人
[确认]D
我想这题是不是应该选E,因为虽然(1)和(2)分别都能得出答案,但答案均是不可能的:I为400,而得出430。
36.k is a 2-digit positive integer, the value of k is 6 times of the unit digit, what is the value of k? D
(1). the ten digit is 4 greater than unit digit.
(2). the sum of the two digits is a two-digit integer.
答案为B,理由同上,不可能的数不应该是SUFFICIENT。
37. the costs $54.64, exclusive tax. $0.79 is added, at 5% tax rate to the taxable items. The untaxed costs=? 38.84
这一题题目很搞:54。64不含税,那么答案还应该是38.84。
思路:TOTOAL COST=UNTAXED COST+TAXED COST+TAX现根据提议,54.64为不含税的COST,应=UNTAXED COST+TAXED COST,即:54.64=UT COST+0.79/0.05 答案应该是38.84
42. (-1)^k+1/2^k前十项的和。
A. 大于2,B. 1和1/2之间,C. 1/2和1/4之间,D.小于1/4
应该是B
由于-1的1至10次方相加和为0,这一题可化简为1/2~K的前十项和应该是B。
以下是引用rushcynthia在2003-1-6 12:18:46的发言:
刚刚才看到斑竹对11题的确认,不好意思,那个问题就解决了.下面的这个我对答案也有疑义
请指教
1. Is X<0?
a.) X^3 < 0
b.) X^2+X+1 =0
我认为b也对,(x^2+1)>=1,只有当x<=-1的时候,b选项的等式才会等于0,所以我认为答案是D
agree with summer02618 about NO 42,36,35. NO17 is similar to NO 44, but the question is different, so i think the answer of NO44 is 25pai.
No.21 my answer is C(4,6).
No.51 i think the answer is bb-a=m, and line lintersect quadrant 1,3,4, so mb-a