21+50+15=86 7 G. e: c+ E% q# M3 ?4 Twhy 86...tvb now,tvbnow,bttvb! k# u1 `2 k5 X' B
becos he change 50 "small money" then giv bck to customer 29 and he keep the balance 21 1 r# t8 w5 M1 y9 M! dthen he giv bck his fren 50 ; I* [1 |* i: M; ?: K4 d4 ^1 T- Wand the shoes cost is 15 % u4 F3 f ?8 N( p- q公仔箱論壇 * f/ ?0 V2 [3 B8 mso total he loss is 86...公仔箱論壇8 t' O) n k3 N W& m- L+ `
# G! ?4 V. B: }" f( q! b[ 本帖最後由 ooichse 於 2008-12-3 01:54 AM 編輯 ]