21+50+15=86' n! D3 i) c. }9 `, ^: z4 n7 T
why 86...TVBNOW 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。7 e1 b: V& g6 _5 s6 y
becos he change 50 "small money" then giv bck to customer 29 and he keep the balance 21% D+ e$ Q# b5 S; p+ x
then he giv bck his fren 50& C0 [# X/ m. W9 O5 g4 T% t# J
and the shoes cost is 15TVBNOW 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。5 G x/ S0 x, p' W; l3 Z8 }) s
+ Y& u9 n9 g1 O
so total he loss is 86...! R6 }' Y+ M$ q- N