Store S sold a toat of 90 copies of a certain book during the seven days of last week, and it sold different numbers of copies on any two of the days. If for the seven days Store S sold the greatest number of copies on Saturday and the second greatest number of the copies on Friady, did Store S sell more than 11 copies on Friday?
1. Last week store S sold 8 copies of the book on Thursday.
2. Last week store S sold 38 copies of the book on Saturday.
Answer: B
请问高手,如何快速地在2分钟内解出这题?我脑子有点膨胀。
设FRIDAY是X,因为每天都不同,使得X最小的情形是:38+x+x-1+x-2+x-3+x-4+x-5=90
6x=67
x=67/6>11
欢迎光临 国际顶尖MBA申请交流平台--TOPWAY MBA (http://forum.topway.org/) | Powered by Discuz! 7.2 |