1. A truck is traveling at a speed of 20 miles/hour in the first half trip, then 30 miles/hour in one third of the total trip. What is the average speed?
【机委】 24
2. 50.A graph like this. The angles in the top half are x, 2x, 2x, 2x, and 3x. How much is y?
/\\2x
2x/ \\2x
| |3x
| /|y
x |/_ |
【讨论】 18
3. DS: 两班学生考试, A and B, the scores show that means of A and B are 84 and 78, respectively, Median of A and B are 75 and 82, respectively. Does the mean of A+B greater than the median of A+B?
1) I forgot… 2) the number of students in A and B is 43 and 37.
【讨论】条件1待补充，由条件2可得A+B 的mean0 ,( x/(x+y))^10 + ( y/(x+y) )^20 = k ， x0, xy^2z是否大于0?(1)y<0(2)x>0
【确认】B
I think the answer is A
10. DS:20个家长选择周一到周五开家长会,周三的家长多于周二的家长,问周五是否有至少一个家长选择
1)没有一天的家长数超过5个 2)周三的家长多余周一的
【确定】A
如果（1）是大于5则A 如果是大于等于5则为C 对吗？？？作者: tongxun 时间: 2002-10-9 22:58
