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~( U: O4 P x% h/ w* R
5.39.217.77:88986 B$ ]3 {) p* ] _8 W
[ 本帖最後由 carsonchan 於 2009-2-15 04:18 PM 編輯 ] |