31.
有一题ETS明显想害我们,就是知道一坐标点(5,a)问斜率,DS,这次ETS加了个条件:a不等于5,选项一样,不过答案嘛——只选(a,5)那项就行了。
[确认]B
[思路]参见以前JJ
*[附]OLD JJ:
On XY plane. If a line goes through Point A (A, 5), Is the slope of the line<0?
a. Line goes through (0, -2)
b. Line goes through (5, A)
[讨论] B;
是E,如果A=5呢?
我还是认为是E,因为题目没有说明A不能等于5,因为条件再说明一次直线经过点(5.5)是没错,也不是没意义,以前也有些题目是A.B里是再说一次题目的条件,我认为这可算是陷阱,因为我们不能自己删除了A=5的可能性,最重要是题目没说A的限定条件。我们就得考虑所有可能性。
*
掺沙那道题有,还有一道据说也是JJ吧:总数88个坏RADIO,许多修理工拿走同样数目的RADIO去修理,剩余数为“2 less than numbers of”修理工拿走的,问每个修理工拿走的数不可能是几?这里我就糊涂了,是和总数一样多呢,还是和每个工人拿的数一样呢?答案分别是:5,9,12,15,18,按总数算答案是没有的,于是只好按“比每个人的数多2”算了,答案就是12了。
[讨论] 12。有点象第29题。
又演砸了(12.30jj) Robert之家 发表于 2003-1-1 14:38:12
49. integer a
a) b=c-1
b) a=d-3
ans: B
[讨论]题目不清楚。
50. integer x, the unit digital of (x+1)^2 and (x+3)^2 is 1, what is the unit digital of (x-3)^2?
ans: 5
[确认] 5
51. line l parallel line y=x and intersect quadrant I, III, IV, and point (a, b) on line l, what is the relation of?
[讨论] a=b ?
52. m, n positive integer, what is the value of mn?
a) m/n=7/15
b) the greatest common divisor of m, n is 3
ans: C
[确认] C
53. The policy of a telecommunication company charge: month rate (above 75 messages) 80% of the original fee $10,
one message charge: (above 75 messages) $0.065, what is the total fee of a customer consumes 95 message a month charged by the company?
[确认] 0.065*95+10*80%=14.175
54. 2 box, one includes 15 purple and 35 red flowers and the other includes 20 purple and 30 red flowers. Now draw out one flower randomly, ask the possible of that it is purple flower? (number maybe inaccurate)
[确认](15+20)/(15+35+20+30)数据可能有误,记住方法。