how much 7-11 earn from one bottle of drink?

Posted by modo on 2011/10/15 13:16:25

buy one bottle of drink with 18,
and if buy two bottles, the second bottle can get 44% off,
so buy two with 28,
so you save 8,

the question:
at least how much 7-11 earn from one bottle?
i took 10 min to calculate the answer,
how about you?