[Solved] A mile long train is moving at 60 miles per hour when it reaches a mile-long tunnel. How long does it take the entire train to pass through the tunnel?

The answer to the riddle is For the train to pass completely through the tunnel, it must travel 2 miles. After 1 mile travel, the train would be completely in the tunnel, and after another mile it would be completely out and since the train is traveling at 1 mile a minute, it will take 2 minutes to pass through the tunnel.