Question

A train of length 180 m crosses a man standing on a platform in 12 seconds and cross another train coming from opposite direction in 12 sec. If the second train running at 2/3 rd speed of the firstthen find the length of the second train?

• A. 56
• B. 120
• C. 20
• D. 44

Answer 1

The correct option is B 120

Length of the first train$=180m$

Time taken by the train to cross the man standing on the platform$=12s$

Speed of the first train$=\frac{180}{12}$

$=15m/s$

Speed of the second train$=\frac{2}{3}\times 15$

$=10m/s$

Relative speed$=15+10$

$=25m/s$

Let the length of the train be $y$ metres.

$Distance=Speed\times time$

$y+180=25\times 12$

$y+180=300$

$y=300-180$

$y=120$

So, the length of the second train$=120m$