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~www3.tvboxnow.com/ ~4 ]& v- Q0 |9 ^
5 w1 h+ \# a, K2 Y, Q, g& n0 x[ 本帖最後由 carsonchan 於 2009-2-15 04:18 PM 編輯 ] |