MATH 问题请教,IN RUSH

yaojun

P.S

1）In Town X, 64%of the population are employed, and 48%of the population are employed males. What percent of the employed people in Town X are females?

a 16% b 25% c 32% d 40% e 52%

2) A certain roller coaster has 3 cars, and a passenger is equally likely to ride in any 1 of the 3 cars each time that passenger rides the roller coaster. if a certain passenger is to ride the roller coaster 3 times, what is the probability that the passenger will ride in each of the 3 cars?

0, 1/9, 2/9, 1/3, 1

D.S

3) IF x and y are positive, is 3x>7y?

1) x > y+4    2) -5x < -14y

4)If w and c are integers, is w> 0?

1 w+c>50      2. c>48

谢谢大家的帮忙，by the way, i am going to take test on June 20th in Toronto, if you are in Toronto and is going to take GMAT, please leave messege to me,maybe we can study with each other. My email is woodland501(A) hotmail.com

liukfylp9

1.A

2.C

3.B

4.E

yaojun

DO   YOU MIND GIVING A LITTLE BIT STEPS, PLEASE?

liukfylp9

1 A 64-48=16

2.C 一共3*3*3=27个组合,1\2\3组合有6种,6/27=2/9

3.E (1)不充分，y<=3时才成立;(2) 把负号去掉,2.5x>7y,x、y为正时3x>7y,为负时不一定，所以也不充分。上面我想错了。请再看看

4.E (1)不充分;(2) 不充分;加起来也不充分,因为w可大于0也可小于0

liukfylp9

3. 对不起,3没看清.题干里说了x,y为正;所以还是C

beautywawa

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oookk

以下是引用liukfylp9在2005-6-11 7:12:00的发言：

1 A 64-48=16

2.C 一共3*3*3=27个组合,1\2\3组合有6种,6/27=2/9

这个题目不明白的说！谁解释详细点

3.E (1)不充分，y<=3时才成立;(2) 把负号去掉,2.5x>7y,x、y为正时3x>7y,为负时不一定，所以也不充分。上面我想错了。请再看看

这个应该是B把？-5x<-14y===》5x>14y====因为X，Y都是正数，所以5X+X也必然大于14y。所以6x>14y====3x>7y!不是么？哪里出问题？也不是C啊

4.E (1)不充分;(2) 不充分;加起来也不充分,因为w可大于0也可小于0

[此贴子已经被作者于2005-6-11 15:11:15编辑过]

blackhorse

更正：第一道应该是B。（64%-48%)/64%=25%

happyfish0517

1.B

2.C...oookk啊，这样，3个人3辆车，随便上车的情况有3^3=27种（每个人都有三种选择上哪辆车）；每辆车各上一个人的情况是3*2*1=6种(第一个人有3种选择上哪辆车，第2个人在剩下的两辆中挑，LAST ONE没的挑...所以6/27=2/9)

3.B

4.E