JATER

假設原本有$10, 用$8買雞, 剩$2公仔箱論壇2 e# P$ |" w+ A2 G. y
之後$9賣出, $2+$9 = $11tvb now,tvbnow,bttvb# G, j5 Q: Y9 W" p* i2 N! y2 ]
再用$10買雞, $11-$10 = $1tvb now,tvbnow,bttvb4 U* e) J1 m' M  ^
又再以$11賣出, $1+$11 = $12
% s3 s5 L! r9 W/ b/ I2 [0 r* J$12-$10 = 賺$2