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~
# g! f# U- K% D1 s2 otvb now,tvbnow,bttvb
% W y9 N( H* q9 d) }: f |! ctvb now,tvbnow,bttvb[ 本帖最後由 carsonchan 於 2009-2-15 04:18 PM 編輯 ] |