Answer:
1: 6hr 2: 25km
Step-by-step explanation:
The equation velocity=distance/time (v=d/t) is useful for these problems.
1: v=100 km/hr, d=600km
plugging into the equation, we get 100km/hr=600km/t
rearrange to get t=600/100, or t=6hr
2: v=50km/hr, t=5hr
plugging in: 50km/hr=d/0.5hr
rearrange: d=(50km/hr)*0.5hr, or d=25km
don't forget your units, and have a lovely day :)