21+50+15=86. o+ U. m( K7 k" l& N
why 86...tvboxnow.com' z0 {$ i' L. O3 X8 A: H
becos he change 50 "small money" then giv bck to customer 29 and he keep the balance 21公仔箱論壇& b" t1 L% R( P0 u" r S
then he giv bck his fren 50公仔箱論壇. h; ]* z" L$ y; s
and the shoes cost is 15
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so total he loss is 86...
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1 b& g, b4 T/ X% l' @& Y* @[ 本帖最後由 ooichse 於 2008-12-3 01:54 AM 編輯 ] |