1. 长方体的长:宽:高 为3:2:2,体积为x, 问用x 表示长,下列正确的是:
a, 3次根号X b, 3次根号3X/2 c, 3次根号2X/3 d, 3/2又3次根号X e, 2/3又3次根号X
======================================================
I got it as 3次根号9X/4.
2. P, Q 在共有5人的队中参加比赛,任何两人不能同时到终点,问使P在Q 前的比赛结果有多少种?(这类题的思路是什么呀?)
=======================================================
I think it should be (P5,5)/2 because P is either ahead of Q or behind Q.
3. 大于700的三位数中有多少两位相同的整数? (机经答案为80,对吗?能简单说下思路吗?
=======================================================
Yeah. They said it was 80. But I got it as 83. I don't know.作者: tongxun 时间: 2002-8-12 02:34
1. 长方体的长:宽:高 为3:2:2,体积为x, 问用x 表示长,下列正确的是:
a, 3次根号X b, 3次根号3X/2 c, 3次根号2X/3 d, 3/2又3次根号X e, 2/3又3次根号X
(没正确答案呀?)
--------------
redpot is right! the reason is that your question is wrong. if 问用x 表示gao, then you can find the answer.
=============
2. P, Q 在共有5人的队中参加比赛,任何两人不能同时到终点,问使P在Q 前的比赛结果有多少种?(这类题的思路是什么呀?)
-------------
I do not agree with redpot. I\II\III\IIII\IIII, there are five positions. 1)P=IIII, p3,3=6;2)p=III, p3,3 * c2,1=12;3)p=II,c3,1 *p3,3=18;4)p=I,p4,4=24.
6+12+18+24=60
=========
3. 大于700的三位数中有多少两位相同的整数? (机经答案为80,对吗?能简单说下思路吗?
----------
707,717....797; ----10-1=9. 711,722,...777,..799---9-1=8.
800,900
808,..888,..898;----9. 811..............899---8
909, ----9. 911..............999---8
redpot,how can you get 83????作者: redpot 时间: 2002-8-18 11:23
I am sorry. The correct answer should be 80. Pls refer to Ianwang's "大于七百的三位数中有多少两位相同的整数(80)详解 ". As to No.2, you got the same answer as what I did.作者: wjpjason 时间: 2002-8-25 00:29