假設原本有$10, 用$8買雞, 剩$2
1 [2 }# ^5 c2 _tvb now,tvbnow,bttvb之後$9賣出, $2+$9 = $11
( d: |1 C! E) [& `. \! d' H! s5.39.217.76再用$10買雞, $11-$10 = $1tvb now,tvbnow,bttvb' w& P8 |4 @+ F, {% M. @7 F4 X3 d
又再以$11賣出, $1+$11 = $12 f# h7 W ^7 u4 w a# @, A* ?2 E/ z
$12-$10 = 賺$2 |