3-18 jj贡献 Boston

335700t

7(DS)  X 有３位数，　可被３　整除。个位是十位的２　倍。问哪个must be true?

          (1)十位上不能是零。

　　　（２）是偶数（谁是偶数忘了）

　　　（３）是奇数　　（谁是忘了）

　　　　（４）是PRIME?

          (5) 忘了

should be (2) 

I don't get it for this question. According to the question stem 个位是十位的２　倍 If 十位 is 0, how can 个位是十位的２　倍. Also, I agree 个位 has to be EVEN.

335700t

Hi ,wangxiaoqing   How are you? You math is really good,

DO  you know how to solve this question? Thanks! 一个场所450个座。如果每ROW 递增3 个座位会比平均每ROW 一样的座位少5 Row。求Row？

[此贴子已经被作者于2009-3-20 4:23:50编辑过]

jenn9fer2003

hi, i am in boston. taking gmat on 3/20.

wangxiaoqing

Hi ,wangxiaoqing   How are you? You math is really good,

DO  you know how to solve this question? Thanks! 一个场所450个座。如果每ROW 递增3 个座位会比平均每ROW 一样的座位少5 Row。求Row？

R= number of rows

S= seats per row

RS=450

(R-5)(S+3)=450

Can try to solve it

or 30*15=450

(30-5)(15+3)=450; just try each choice, it will be faster

so R is 30

wangxiaoqing

7(DS)  X 有３位数，　可被３　整除。个位是十位的２　倍。问哪个must be true?

          (1)十位上不能是零。

　　　（２）是偶数（谁是偶数忘了）

　　　（３）是奇数　　（谁是忘了）

　　　　（４）是PRIME?

          (5) 忘了

should be (2) 

I
don't get it for this question. According to the question stem
个位是十位的２　倍 If 十位 is 0, how can 个位是十位的２　倍. Also, I agree 个位 has to be
EVEN.

(1) ex: can be 300; think about the relation B=2A; if A=1, B=2, or A=0, B=0
so 十位数 can be 0

abcde8962

6（DS）：一个Set 有5个数。给了4 个数（3560， 3360， 3400， 3390 可能不准，
            但很接近）求第5个数是多少。

       （1）：Range 是 220

        (2):  Median 是 3390         我选的
            C  

first order these numbers

3360,3390,3400,3560

(1) could be 3360+220 or 3560-220

(2) means that 3390 is the third number, b/c median for 5 numbers are the third number
so we know the fifth number is 3560

so answer should be B

It's good to think about this way. Maybe I misleading you. I mean: The set has 5 Numbers, we need to find out the missing one.( But in case, it is good to know this situation)

335700t

 I feel that we work like spy! Thanks! Brother!

[此贴子已经被作者于2009-3-22 6:05:10编辑过]

335700t

jenn9fer2003

Hi girl, good luck!

wangxiaoqing

 to wangxiaoqing

Hi
brother. Thanks a lot! I will die for sure on 31-03. My math is
terrible. What I need at least over 500; probably, I am the lowest
level here. It doesn't matter; I have to do what I have to do.

However, I have to try my best. Can I sent email to you to ask some math question? My email is tiansandra[在] yahoo.com.cn. I would appreciate any suggestion you give to me.Thanks again!

Hi, I can not give you my email. Do not disclose any of your personal information here. I think GMAC probably knows about CD and is hiring some hanjian of China to spy on this website. I think it would be good if we can discuss problems here so that everyone can benefit. 

wangxiaoqing

6（DS）：一个Set 有5个数。给了4 个数（3560， 3360， 3400， 3390 可能不准，
            但很接近）求第5个数是多少。

       （1）：Range 是 220

        (2):  Median 是 3390         我选的
        C  

first order these numbers

3360,3390,3400,3560

(1) could be 3360+220 or 3560-220

(2) means that 3390 is the third number, but can not find the missing number

(1)+(2)
we know the largest is 3560, the range is 220, so the missing must be 3560-220

so the answer is C