64seconds2 F- q, e& ^8 h* u D0 g# o
公仔箱論壇9 W Y5 e: y3 a, y5 H# }
1 to 4 have 3floors = 48 sec公仔箱論壇, P$ @) E0 _& ]& B9 n, z! S
avg. 48/3 = 16sec( {: h; l5 ?7 n9 @3 D: L
$ f8 p! K7 n9 }# P( G
4 to 8 have 4floors = 16x4tvb now,tvbnow,bttvb2 h0 V6 d$ k2 w! u* K6 e
= 64secs |