64seconds
9 c6 b$ K' S) W3 c5.39.217.77
! Q0 Q/ a/ `1 M8 y y5 w; P# I5 l5.39.217.771 to 4 have 3floors = 48 sec
8 s) t v- ]" P$ h! o m, Cavg. 48/3 = 16sec
4 V/ X# u8 z/ o1 p- T8 Z9 F0 _% e公仔箱論壇
9 L% @" @, t& B& N3 x! e4 to 8 have 4floors = 16x4
% L( F$ [9 T$ d8 z H; l2 f& C= 64secs |