21+50+15=86' f0 c/ O. k& U+ k% V
why 86... ( D7 T9 D9 }+ j& hTVBNOW 含有熱門話題,最新最快電視,軟體,遊戲,電影,動漫及日常生活及興趣交流等資訊。becos he change 50 "small money" then giv bck to customer 29 and he keep the balance 21公仔箱論壇$ E3 O/ w' k# G# l4 l* u6 k
then he giv bck his fren 50TVBNOW 含有熱門話題,最新最快電視,軟體,遊戲,電影,動漫及日常生活及興趣交流等資訊。+ _& s& T& p) ]% o& j0 ?5 J
and the shoes cost is 15 * M( X- |3 f: g- t7 ?9 t3 p8 i1 ]5 p
so total he loss is 86...' t. P7 q2 J4 I- b; d6 Z Q
- S1 G+ l3 X. X* s
[ 本帖最後由 ooichse 於 2008-12-3 01:54 AM 編輯 ]