Step-by-step explanation:
here they gave 12 km are reached by 2.5 hours so we. should how much time they took for 1km
12/ 2.5 which is also 150min
12km which is also 12000
12000/150= 80m
it took 80m in 1min so
1hr = 60min
1hr x 80m
60x80
4800
convert it intlo km
4800/1000
4.8km
so it took 4.8 km for 1hour