A train travelling at a speed of 75 mph enters a tunnel 3.5 miles long. The train is 0.25 mile long. How long does it take for the train to pass through the tunnel from the moment the front enters to the moment the rear emerges?

Question: A train travelling at a speed of 75 mph enters a tunnel 3.5 miles long. The train is 0.25 mile long. How long does it take for the train to pass through the tunnel from the moment the front enters to the moment the rear emerges?

Solution:
Total distance covered = 3.5 + 0.25 mile = 3.75 miles
Train traveles 75 miles in 60 min
∴ Train traveles 3.75 mile in (60 × 3.75)/75 min
= 3 min