标题: 求大神解答两道数学题，万分感谢！！！！！ [打印本页] 作者: KKYan 时间: 2016-10-24 02:31 标题: 求大神解答两道数学题，万分感谢！！！！！ 1. Amy and Jed among the 35 people, who are standing in a line, one behind the other, waiting to buy movie tickets. The number of people in front of Amy plus the number of people behind Jed is 24. If there are 15 people behind Amy, including Jed, how many people are in front of Jed?
A. 23
B. 25
C. 27
D. 29
E. 31
2.
For the region in which the ranges of dollar amounts of the four expense categories was least, what percent of total living expense was the Transportation expense in that region?
A. 10%
B. 15%
C. 16%
D. 17%
E. 20%
答案：1. E（我选的 D）;2. C（我选的 E） 作者: 不及雨 时间: 2016-11-1 05:07
amy前设为x，amy jed中间设成z，jed后设成y。 三个方程联立：x + z = 15, x + y = 24, x + y + z =35 => z = 11, x = 20, y =4 所以选择E 作者: 不及雨 时间: 2016-11-1 05:09
下面那道题 range 是极差作者: seekingblackswa 时间: 2016-11-12 13:28
第一题选D没有错。