A train that is 1 mile long starts through a tunnel that is also 1 mile long. The train is traveling 15 miles per hour. How long does it take for the train to get completely out of the tunnel?

Answer 1

It takes 1/15 hour for the engine to enter and leave the tunnel

When the engine is leaving, the caboose is entering, and also takes 1/15 hour to pass through the tunnel.

Answer is 1/15 + 1/15 = 8 minutes.

Answer 2

8 minutes