Answer:
Explanation:
at the end of; Karabo John
1st hour 80km 0km(bcause he hasn't started)
2nd hour 160 km 100km
3rd hour 240 km 200km
4th hour 300 km 300km
now I'm not sure whether we should consider the time period after the starting time of karabo, or that of John (they have a gap of one hour u know..)
so, from the starting time of karabo, it takes 4 hours, and from the starting time of John it's 3hours. (Because John started 1 hour later)