A train 800 m long can cross an electric pole in 20 sec and then find the speed of the train?  Choose the correct choice from the following options:
A) 87 kmph
B) 97 kmph
C) 72 kmph
D) 144 kmph
E) 120 kmph

Rationale: "length = speed * time speed = l / t s = 800 / 20 s = 40 m / sec speed = 40 * 18 / 5 ( to convert m / sec in to kmph multiply by 18 / 5 ) speed = 144 kmph answer : d"
Answer: D