64seconds
$ J6 y3 ^8 o- n2 j4 r' Y, D
" K% G7 ?* k) l5.39.217.761 to 4 have 3floors = 48 sec
6 {' Q& w/ b1 X: l' N8 A* s5.39.217.76avg. 48/3 = 16sec) ^) i, r; L' r) O6 m/ E: `$ g# I
9 b$ Q, p- [) J: G( u4 u2 d1 L5 _. O公仔箱論壇4 to 8 have 4floors = 16x4
T h6 l: p* f' I `= 64secs |