请教数学题2

shirleywang

题号和cd gwd 不同

gwd10  30题

  If n is a positive integer, what is the value of the hundreds digit of 30^n?

  1) 30^n >1000

  2) n is a multiple of 3

key A

  gwd 37

In a meeting of 3 representatives from each of 6 different companies, each person shook hands with every person not from his or her own company. If the representatives did not shake hands with people from their own company, how many handshakes took place?

  key 35

啊！！不会

10题

Is |x|<1?

1) |X+1|=2|x-1|

2) |x-3|不等于0

11 题

The product of the units digit, the tens digit, and the hundres digit of the positvie integer m is 96, what is the units digit of m?

1) m is odd

2) The numbers digit of m is 8

多谢大家

hitlzc

gwd10  30题
  If n is a positive integer, what is the value of the hundreds digit of 30^n?
  1) 30^n >1000
  2) n is a multiple of 3
key A

30^n=3^n*10^n>10^3

n>=3

30^n>=9000,所以百位是0

11 题

The product of the units digit, the tens digit, and the hundres digit of the positvie integer m is 96, what is the units digit of m?

1) m is odd

2) The numbers digit of m is 8

96=3*2^5

1)m为奇数的话，个位为奇数，有96的分解来看，个位只能是3

10题

Is |x|<1?

1) |X+1|=2|x-1|

2) |x-3|不等于0

1）X>=1时,X+1=2(X-1),X=3,-1=<X<1时，X+1=2(1-X)，X=1/3,X<-1时，无解。

2）|x-3|不等于0，X不等于3。

综合二者，所以X=1/3, |x|<1。选C

[此贴子已经被作者于2006-2-11 8:36:01编辑过]

入画

The numbers digit of m is 8 怎么翻译啊，是说M是个8位数吗？

shirleywang

hundreds digit  是百位

tens digit 是十位

unit digit 是个位

入画

如果说 THe hundreds digit of M is 8. 我明白，是M的百位数是8

那The numbers digit of m is 8 怎么翻译啊

hitlzc

以下是引用入画在2006-2-11 20:59:00的发言：

如果说 THe hundreds digit of M is 8. 我明白，是M的百位数是8

那The numbers digit of m is 8 怎么翻译啊

貌似是你理解的意思吧。但我怎么觉得表达有点怪。

我觉得the digits numbers of m更好点吧

不确定。