1. The points A, B, C, and D are on a number line, not necessarily in that order. If the distance between A and B is 18 and the distance between C and D is 8, what is the distance between B and D? (1) The distance between C and A is the same as the distance between C and B (2) A is to the left of D on the number line
Key:E 我选了A，估计是落掉了一些情况，请赐教！
2. If Z^n =1, what is the value of z? (1) n is a nonzero integer (2) z>0 key: C 我选了A, 感觉即便是Z<0,如果要Z^n =1，z也只能等于1吧？还能等于别的？？不解
3. if x>y^2>z^4, which of the following statements could be true? I. x>y>z II. z>y>x III. x>z>y A. I only B. I and II only C. I and III only D. II and III only E. I, II, and III key: E 做这种题我通常是带入一些数，但是经常会漏掉一些情况，所以这种题对我很头疼。我选了Ｂ不知道大家又没有什么好的办法来做这种题？谢了！
3. Henry purchased 3 items during a sale. He received a 20 percent discount off the regular price of the most expensive item and a 10 percent discount off the regular price of each of the other 2 items. Was the total amount of the 3 discounts greater than 15 percent of the sum of the regular prices of the 3 items? (1) the regular price of the most expensive item was $50, and the regualr price of the next most expensive item was $20. (2) the regular price of the least expensive item was $15 key: A 我的方程式：(20%*A+10%*B+10%*c)/(a+b+c),看了答案，突然想起来可以用＄２０来代替ｃ，接出来的值好像比１５％大，可是问题是分子分母都还有Ｃ，怎么确定最后的值比这个大还是小呢？
作者: yedeanboy 时间: 2007-8-24 02:55
1. The points A, B, C, and D are on a number line, not necessarily in that order. If the distance between A and B is 18 and the distance between C and D is 8, what is the distance between B and D? (1) The distance between C and A is the same as the distance between C and B (2) A is to the left of D on the number line
不知道说清楚没有？ 作者: yedeanboy 时间: 2007-8-24 02:58
2. If Z^n =1, what is the value of z? (1) n is a nonzero integer (2) z>0 key: C
(1)无法推出z的值，因为当n为偶数时，z可以等于1或者-1 （2）z大于0单独自然也无法推出z的值 两者合并得到，z>0 并且z=1或者-1，所以z必然等于1 作者: yedeanboy 时间: 2007-8-24 03:01
3. if x>y^2>z^4, which of the following statements could be true? I. x>y>z II. z>y>x III. x>z>y A. I only B. I and II only C. I and III only D. II and III only E. I, II, and III key: E
一般分析y和z大于1或者小于1大于0的情况，因为平方或者4次方会放大大于1的数而减小小于1的数 这类题确实很麻烦，很容易错。 作者: yedeanboy 时间: 2007-8-24 03:07
3. Henry purchased 3 items during a sale. He received a 20 percent discount off the regular price of the most expensive item and a 10 percent discount off the regular price of each of the other 2 items. Was the total amount of the 3 discounts greater than 15 percent of the sum of the regular prices of the 3 items? (1) the regular price of the most expensive item was $50, and the regualr price of the next most expensive item was $20. (2) the regular price of the least expensive item was $15 key: A
所以选A 作者: Drakedirect 时间: 2007-8-24 03:12 yedeanboy，第一题的思路果然清晰，我做的时候画了半天，费了好多时间，还是做错了，按照你讲很容易就选Ｅ了。每次看到这种题目，脑子就乱了，不知道从哪里下手！作者: Drakedirect 时间: 2007-8-24 03:12
第二题，是我忘记了－１的情况．．．哎，总是丢三落四的．．．多谢作者: Drakedirect 时间: 2007-8-24 03:17
第三题找到一个：25>9^1/2>16^1/4, x>z>y,其实这样的例子还很多，可是考试时一有时间的压力，脑子就想不出来了，多谢yedeanboy提醒 作者: Drakedirect 时间: 2007-8-24 03:23
3. Henry purchased 3 items during a sale. He received a 20 percent discount off the regular price of the most expensive item and a 10 percent discount off the regular price of each of the other 2 items. Was the total amount of the 3 discounts greater than 15 percent of the sum of the regular prices of the 3 items? (1) the regular price of the most expensive item was $50, and the regualr price of the next most expensive item was $20. (2) the regular price of the least expensive item was $15 key: A
