PREP数学难题求助高人~

manor90

The table shows the number of shares of each of the 5 stocks owned by Mr. Sami. If Mr. Sami was to sell 20 shares of Stock X and buy 24 shares of Stock Y, what would be the increase in the range of the numbers of shares of the 5 stocks owned by Mr. Sami?

Stock	No. of shares
V	68
W	112
X	56
Y	94
Z	45

A.4B.6 C9.D.15E.20

海砂516

不是数学高人- -
在S没有买卖之前， range=最大-最小= 112- 45=67
买卖之后最大成了94+24  最小成了56-20 新的range=82
82-67=答案

matrixgtx

我是这么做的：变动之前是112-45=67,变动之后是（94+24）-（56-20）=82，相减就是82-67=15,选D，不知对不对