Answer:
10 km/h
Step-by-step explanation:
You want the speed of one of two trains that meet after the first one has a 14-hour head start. The time and speed of the second train are given.
The relation between time, speed, and distance is ...
distance = speed × time
distance = (45 km/h)(4 h) = 180 km
The diesel train catches the cattle train after they both have traveled 180 km.
The cattle train travels 14 hours before the diesel train starts plus the 4 hours after the diesel train starts by the time the two trains meet. In that 18 hours, it has also traveled 180 km. Its average speed is ...
speed = distance / time
speed = (180 km)/(18 h) = 10 km/h
The speed of the cattle train is 10 km/h.