Question

A train traveling at 30 miles per hour reaches a tunnel which is 9 times as long as the train. If the train takes 2 minutes to completely clear the tunnel, how long is the train in miles? (1 mile= 5,280 feet)

Answer 1

Total Length covered by the train to be completely of out of the tunnel = Length of the Train + Length of Tunnel

Length of Tunnel = 9 Times as long as Length of Train

Total Length covered by the train to be completely of out of the tunnel = Length of Train + [9 X ( Length of Train )] = 10 (Length of train) --- Equation 1

Time taken = 2 mins = 2/60 hours == 0.03333 hours
Speed = 30 mph

Now, Total Length covered by the train to be completely of out of the tunnel == Speed x Time == 30 x 0.03333 miles = 0.9999 = approx 1 mile === Equation 2

From Equation 1 and 2
1 mile = 10 X Length of Train

So, Length of Train = 0.1 mile = 0.1 x 5280 feet = 528 feet !! Your Answer