64seconds+ j% |6 a+ u$ F1 [3 B
- I6 f; b2 V; q; C. p) P3 K! Utvb now,tvbnow,bttvb1 to 4 have 3floors = 48 sec
/ {' F, S( s% f. |& o, C" cavg. 48/3 = 16sec9 ]/ _1 D$ R. t; I2 G" |0 \6 g
! o0 `, }) L" g; S5 R5 a5 ?
4 to 8 have 4floors = 16x42 B: @$ g" Q' y3 Y8 k5 u
= 64secs |