求教几道，prep数学题，一点儿思路都没有。谢谢

francislaw

谢谢，ALGT的分析，果然犀利，直接道破啊

hexiaoyulee

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

The table shows the number of shared 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 could be the increase in the range of the numbers of shares of the 5 stocks owned by Mr Sami?

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卖之前的range是w-z=112-45=67

hexiaoyulee

楼上写错了，不好意思，没注意看已经解决了

DMelody

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 regular price of the 3 discounts greater than 15 percent of the sume of the regular prices of the 3 items?
（1） the regular price of the most expensive itme was $50, and the regular price of the next most expensive item was $20.
(2) the regular price of the least expensive item was $15.


这一道还是不是很懂阿 求解释啊