A train, 0.25 miles long, going at a speed of 40mph enters a tunnel that is 2.25 miles long.

How long does it take for all of the train to pass through the tunnel from the moment the front enters it, to the moment the rear emerges?

3 minutes 45 seconds

Add the train length (0.25 miles) to the tunnel length (2.25 miles) and multiply by the number of minutes per mile covered (60/40, or 1.5).

2.5 x 1.5 = 3.75

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