Answer:
t = 11.1 hours
Step-by-step explanation:
The question says that, "A mobile advances at 20 m / s and travels a distance of 800 km. Determine the time in hours you use".
Given that,
Speed of a mobile, v = 20 m/s = 72 km/h
Distance, d = 800 km
We know that,
Speed = distance/time
So,

So, it will take 11.1 hours.