假設原本有$10, 用$8買雞, 剩$2
: P0 }/ J! u# X; X' N+ K- v5.39.217.76之後$9賣出, $2+$9 = $11
! C% {, A$ |; q; O1 j1 W( ~7 Q! v, Rtvb now,tvbnow,bttvb再用$10買雞, $11-$10 = $1
5 _( D" m& u% v7 x$ o, L6 e( R又再以$11賣出, $1+$11 = $12: B5 ^% T# O+ k: R9 F+ t! I: E9 V
$12-$10 = 賺$2 |