[转帖]求解题思路

JINMINGRUI

110..有一道是老机经，但是略微有一些不同，
a factory produce A and mail product to customors, mail fee is 19.xx. Sale price is 29.xx/each. ask: how many the factory sell its product to customor this time?
i, its total profit this time is between 280 and 315
ii, its total profit this time is between 300 and 335
The answer should be A , the old JJ　是total revenue, 我考试的时候是total profit
【讨论】i, its total profit this time is between 280 and 315可能打错了，也许应该是total revenue吧，所以选A。
根据上面的题目，应该选E。

究竟该选什么？如何解答，请指点，先谢了！