求助数学题(急)

Elynn_Chen

1,靠这两个条件肯定不能单独判断，不可以选A或B。

(1)m-3z>0

(2)4z-m>0

两个条件联立：

（1）+（2）推出 z>0

  4（1）+3（2）推出m>0

所以z+m>0 选C

2,what would be the increase in the range of the numbers of shares of the 5 stock owned by Mr.Sami? 这句话问的是：在Mr.Sami was to sell 20 shares of stock X and buy 24 shares of stock Y之后这5支股票的持有数量的range的变化（具体地说是增加了多少）

sell 20 shares of stock X and buy 24 shares of stock Y之前：range=112-45=67

stock	Number of shares
V	68
W	112
X	56
Y	94
Z	45

sell 20 shares of stock X and buy 24 shares of stock Y之后：range=118-36=82

stock	Number of shares
V	68
W	112
X	56-20=36
Y	94+24=118
Z	45

所以，the increase in the range of the numbers of shares of the 5 stock =82-67=15 选D

[此贴子已经被作者于2007-5-1 20:46:01编辑过]