# Easy Time, Speed & Distance Solved QuestionAptitude Discussion

 Q. A train running at the speed of 20 m/s crosses a pole in 24 sec less than the time it requires to cross a platform thrice its length at the same speed. What is the length of the train?
 ✖ A. 150 m ✖ B. 200 m ✖ C. 180 m ✔ D. 160 m

Solution:
Option(D) is correct

Let the length of the train be $x$ m.

So, the length of the platform = $3x$ m.

Time taken in crossing the platform = $\dfrac{4x}{20}$sec

Time taken in crossing the pole = $\dfrac{x}{20}$ sec

$\Rightarrow \dfrac{x}{20}+24=\dfrac{4x}{20}$

$⇒ x$ = 160 m