这道题想不通阿,请牛人指点

sailing198961

Store S sold a total of 90 copies of a certain book during the seven days last week and it sold different numbers of copies on any 2 days. If for the seven days Store S sold the greatest number of copies on Saturday and the second greatest number of copies on Firday, did Store S sell more than 11 copies on Friday?

(1) Last week Store S sold 8 copies on Thursday
(2) Last week Store S sold 38 copies on Saturday


OA B

gavenxsn

非N~条件一：如果周四卖8本书的话，假设除了周五和周六之外其他天数卖的书都小于8本取4,5,6,7，加周四就有30本。那周五周六都要大于8，那么周六卖50的话周四就只卖了10本。如果周六卖了48本，周四则有12本。条件能上能下，不选。条件二：周六卖38本，剩下52本，周五卖11本的话，那其他的就算最大，6，7,8,9,10，也只能卖51本，那周五只能卖大于11本等式才成立。B可以。方法有点笨，仅供参考。