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~5.39.217.77: K5 ` V* U& m, P4 k5 d5 R+ T4 p4 z- h
2 w4 [' k: |. K. l- V9 y; D公仔箱論壇[ 本帖最後由 carsonchan 於 2009-2-15 04:18 PM 編輯 ] |