cost 15 to make the shoes, gave the boy 29 for change, and need 29 more to pay back the nieghborhood, so 15+29+29= 73. simple ,math problem. much easier than calculus~
! k1 N# G& R/ h2 M% b1 I公仔箱論壇
& t" a3 w; E$ n+ G0 F2 ^7 j[ 本帖最後由 carsonchan 於 2009-2-15 04:18 PM 編輯 ] |