tolong no 3 ya pakai cara

Kecepatan = Jarak : Waktu
                  = 1,2 : 10/60
                  = 6/5 x 60/10
                  = 6/5 x 6
                  = 36/5
                  = 7 1/5
                  = 7,2 km/jam

Semoga Membantu :)