A train leaves Little Rock Arkansas and travels north at 85

A train leaves Little Rock. Arkansas, and travels north at 85 kilometers per hour. Another tram leaves at the same time and travels south at 55 kilometers per hour. How long will it take before they are 560 kilometers apart? It will take hours.

Solution

Train A - 85 km/h
Train B - 55 km/h
Since they are moving away from each other add the speeds

combined speed = 85 + 55 = 140 km/h

Distance = 560km
time = 560/140
time = 4 hours