64seconds
* v' S3 `% z t) A2 y% q
* J' K, a" |# U- _) E1 to 4 have 3floors = 48 sec
9 d5 b/ R* N$ `/ U; [( B i3 y7 l5.39.217.76avg. 48/3 = 16sec
' [0 W1 f1 f3 z( q9 Utvb now,tvbnow,bttvb0 T: u/ Z2 y: m& s# h1 V/ u; P, l! J
4 to 8 have 4floors = 16x4
& F1 U9 i/ g5 y! r= 64secs |