Jawabanmu

2014-09-03T13:20:23+07:00
Jarak = 60 km
waktu = 10.00 - 8.30 = 1 jam 30 menit
kec. rata2 =jarak : waktu
               = 60km / 1,5 jam = 40km/jam
2014-09-03T13:23:09+07:00
Dik: S = 60Km
       T = 90 menit
Dit: V?
Jwb: V = S/T 
           60/1,5 = 40 km/jam