Question

a train take 18sec tp pass thourgh a platform 162m long and 15sec to pass thourgh another platform 120m long. the lenght of the train ( in m) is

Answer 1

A train takes 18 seconds to pass through a platform 162 m long and 15 seconds to pass through another platform 120 m long then the length of the train is?

Answer

4

Follow

Request

More

5 ANSWERS



K S Narayanan, former General Manager - Revenue Assurance at Aircel Limited (2007-2009)

Answered Feb 4

Simple question of TSD

Smart Method :

The train covers 162 - 120 = 42 m in 18 - 15 = 3 seconds.

=> Speed of train = 42/3 = 14 m/s

The train covers 18 x 14 = 252 m in 18 seconds.

=> Length of train = 252 - 162 = 90 m.

Traditional Method :

Let length of train = L

In first case, train covers 162 + L m in 18 seconds and in second case train covers 120 + L m in 15 seconds.

Speeds are (162 + L)/18 and (120 + L)/15 respectively.

But they are equal.

=> (162 + L)15 = (120 + L)18

=> 2430 - 2160 = 3L

=> L = 270/3 = 90 m