64seconds
7 I( `, ~# {9 M) S a5 \) P$ H$ t- l- E) O6 w
1 to 4 have 3floors = 48 sec
7 ?5 {! {$ S( j5 R$ Savg. 48/3 = 16sec
7 P; b J7 l- I" e% C; D+ J) uos.tvboxnow.com/ E P* C/ c! h5 S! U. F2 | l
4 to 8 have 4floors = 16x4os.tvboxnow.com! K* D9 W# _/ ~; j! X1 k4 \: _
= 64secs |