495.Y 是否是XYZ的MEDIAN
A X》Y+Z
B Y=Z
[确认]B
(*如何理解题意? Y是否median ,if y=z ,should we say y is the median or z is the median since they are the same number? X=1,y=1,z=2 can we say x is median , y is median too?)
489 V,R,T 都为整数,问v^2*R*t^(-1/4)>0?
1)R>V^2
2) R>t^(-1/4)
[确认]D
(*要考虑v=0的情况。E)
416.求1998和1999change of the percentage in the number 那到
(1)1998 改变了。。。percentage.
(2) 1999 改变了。。。percentage.
.[讨论] E
两个连续的年头,应该是C?
406 DS:一班学生,学AB的##人,学AC的##人,学BC的##人,求共有ABC多少?
A: 学AB人中有9人学C;
B: 学A为#,学B为#,学C为#
[确认]C
(*A)
375. 设XoY=(x-y)/(x+y),现5o4=yo3,求Y
[确认]4/15
(*我算得15/4
361. 0.n68 中n=? (n为正整数)
1). n<5
2). 0.n68<1/n2
[确认]E
(*B 吧?n只能取1,取2就错了
357.卖轿车97年比96年收入下降11%,卡车97年比96年增长7%,总收入增长1%,问96年轿车与卡车销售收入之比。
[确认]2:1
我做1:2
(*同意1:2)
352 DS题,说农场里有animals 60头,其中2/3either猪or牛,问猪(或者牛)的数目是多少?
(1) the number of cow is more than twice as many as the number of pigs.
(2)pigs的数more than 12
[确认]C
我选E
(*我认为是C)
349 。1-99,inclusive,其product为(n+1)n的 multiple 是几分之几?
[确认]2/3
(*这题目什么意思?谁的product ?)
333.绿灯:45秒,黄灯5秒,红灯:50秒.绿黄红依此闪烁.问3分钟内红灯能有多少秒.
[确认]80
(*怎么算的呢?我算得100秒)
[em13]作者: tongxun 时间: 2002-12-10 21:11
495. Because y=x=1, the median could be y or x.
489. you are right. We do pay attention on the condition that v is equal to 0.
416. This question is incompleted. Even though it is completed, we must notice that there is a differentia between the number of people in 1993 and in 1994.
406. 1) if anbnc, the answer is A; if aubuc, the answer is C