posted by PLEASEEEEE on .
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?
Use this proportion. Cross multiply and solve for x -- the time it takes the front of the train to go through the tunnel.
15/60 = 1/x
15x = 60
x = 60/15 = 4 minutes for the front of the train to go through the tunnel.
It takes the rear of the train the same time.