-------------------------------公仔箱論壇1 Y+ J( u0 |' A9 r$ C& y: I
8蚊成本卖9蚊=赚1蚊5.39.217.77: x; J& b- S, Z" C0 y) k
再用10蚊买回来=蚀1蚊5.39.217.77+ v, ^$ z/ O' m8 _1 [4 T: [
1-1=0
2 B t" t) [& R g/ u6 X-------------------------------5.39.217.77$ m Z4 K* S: |" h9 I% E
11-10=1蚊5.39.217.77$ M; _) g4 n W" U- j2 t
--------------------------------公仔箱論壇- o! J+ N5 K& z
答案係1蚊? |