Question

A freight rain leaves a station and travels north at a constant rate of 60 mph. One hour later a passenger train leaves the same station traveling north on a parallel track at 80 mph. How long will it take for the passenger train to draw even with the freight train?

Answer 1

since distance = speed * time,

60(t+1) = 80t

Now just find t. That's the time traveled by the faster train.

Answer 2

Or, reason like this:

after 1 hour, the freight train is 60 miles ahead.

Since the passenger train goes 20 mi/hr faster, how long will it take to make up the 60 miles?