bencake

題目誤導人~
, \9 Q# c( B8 g) W" z6 Z# d公仔箱論壇owner 100公仔箱論壇' L3 I* z# B4 W7 ~# H6 [
owner's son 20
+ o% t! K2 G* o. o5.39.217.76each pay 40公仔箱論壇* {$ f0 J: `0 S+ p( i: G
40*3 = 120  T- T5 D+ N: ~
120(3 guys) - 20(owner's son) = 100 (owner)