以下是引用financelover在2007-11-13 6:31:00的发言：10.A certain quantity is measured on two different scales, the R-scale and the S-scale, that are related linearly. Measurements on the R-scale of 6 and 24 correspond to measurements on the S-scale of 30 and 60, respectively. What measurement on the R-scale corresponds to a measurement of 100 on the S-scale?
A. 20
B. 36
C. 48
D. 60
E.84
完全没看懂题目
什么意思啊.
为什么选C?
这就是个对应问题,其实就像我们最开始学函数时用的映射.在X=6和24的时候,Y=30和60,这样就可以建立方程了,比如AX+B=Y,得出A=5/3,B=20,所以当Y=100时,X=48
21. At a garage sale, all of the prices of the items sold were different. If the price of a radio sold at the garage sale was both the 15th highest price and the 20th lowest price among the prices of the items sold, how many items were sold at the garage sale?
A. 33
B. 34
C. 35
D. 36
E. 37
没有思路
收音机的价格正数是15,倒数是20,说明总共有34个价钱.因为每样东西价格都是不一样的,所以就有34个东西在卖.
第15个,说明前面有14个,倒数20个,说明后面有19个,然后加上自己那一个,就34个了
32.If n is a positive integer, what is the value of the hundreds digit of 30n?
(1) 30n > 1,000
(2) n is a multiple of 3.
为什么答案是D啊
N是正整数.首先看1好了.30的N次方可以看做是3的N次方乘10的N次方.如果30的N次方大于1000的话,说明N就大于2了,因为10的2次已经是100了,所以30的N次肯定百位数是0.
2也是同一个道理,其实不用管是不是3的倍数,只要大于2了,百位肯定就是0了
At a garage sale, all of the prices of the items sold were different. If the price of a radio sold at the garage sale was both the 15th highest price and the 20th lowest price among the prices of the items sold, how many items were sold at the garage sale?
A. 33
B. 34
C. 35
D. 36
E. 37
没有思路
收音机的价格正数是15,倒数是20,说明总共有34个价钱.因为每样东西价格都是不一样的,所以就有34个东西在卖.
第15个,说明前面有14个,倒数20个,说明后面有19个,然后加上自己那一个,就34个了
32.If n is a positive integer, what is the value of the hundreds digit of 30n?
(1) 30n > 1,000
(2) n is a multiple of 3.
为什么答案是D啊
N是正整数.首先看1好了.30的N次方可以看做是3的N次方乘10的N次方.如果30的N次方大于1000的话,说明N就大于2了,因为10的2次已经是100了,所以30的N次肯定百位数是0.
2也是同一个道理,其实不用管是不是3的倍数,只要大于2了,百位肯定就是0了
At a garage sale, all of the prices of the items sold were different. If the price of a radio sold at the garage sale was both the 15th highest price and the 20th lowest price among the prices of the items sold, how many items were sold at the garage sale?
A. 33
B. 34
C. 35
D. 36
E. 37
没有思路
收音机的价格正数是15,倒数是20,说明总共有34个价钱.因为每样东西价格都是不一样的,所以就有34个东西在卖.
第15个,说明前面有14个,倒数20个,说明后面有19个,然后加上自己那一个,就34个了
32.If n is a positive integer, what is the value of the hundreds digit of 30n?
(1) 30n > 1,000
(2) n is a multiple of 3.
为什么答案是D啊
N是正整数.首先看1好了.30的N次方可以看做是3的N次方乘10的N次方.如果30的N次方大于1000的话,说明N就大于2了,因为10的2次已经是100了,所以30的N次肯定百位数是0.
2也是同一个道理,其实不用管是不是3的倍数,只要大于2了,百位肯定就是0了
At a garage sale, all of the prices of the items sold were different. If the price of a radio sold at the garage sale was both the 15th highest price and the 20th lowest price among the prices of the items sold, how many items were sold at the garage sale?
A. 33
B. 34
C. 35
D. 36
E. 37
没有思路
重复了...
32.If n is a positive integer, what is the value of the hundreds digit of 30n?
(1) 30n > 1,000
(2) n is a multiple of 3.
为什么答案是D啊
还是重复了... 
