Aptitude 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**