[求助]1题关于gmatprep上的题

wujie_rens

stock number of shares

v 68

w 112

x 56

y 94

z 45

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 range of the number of shares of the 5 stocks owned by Mr Sami?

A 4 B 6 C9 D15 E 20

Answer: D

我认为是A， 24-20=4

moderation

range before transaction

112-45=67

rang after transaction

(94+24)-(56-20)=118-36=82

the difference is

82-67=15

hope it helps~~