A train of length L is traveling at a constant velocity and passes a pole in t seconds. If the same train travelling at the same velocity passes a platform in 4t seconds, then what is the length of the platform?	Choose the correct choice from the following options:
A) 0.5L
B) L
C) 1.5L
D) 2L
E) 3L
The train passes a pole in t seconds, so velocity v = L/t   (L+P)/v = 4t   (L+P) / (L/t) = 4t   P = 3L   The answer is 3L.
<result>E</result>
A train of length L is traveling at a constant velocity and passes a pole in t seconds. If the same train travelling at the same velocity passes a platform in 4t seconds, then what is the length of the platform?