Question

Comprehension

Direction: Study the direction and answer the following questions.

Train Shatabadi Express of length 180 meters can cross a tree in 12 seconds. Another train August express of length 240 meters crosses the tree at the same time as the train Shatabadi. Both the trains entered a bridge of length 270 meters at the same time moving in opposite directions.

What is the time taken by the two trains to cross each other? If the time taken by Shatabadi to cross a tree is 66.67% more and the time taken by August to cross a tree is 150% more. 

1. 24.7
2. 2.80
3. 2.90
4. 3.0
5. 3.2

Answer 1

Correct Answer - Option 1 : 24.7

Given:

Length of train Shatabadi express = 180 m

Length of train August express = 240 m

Time Shatabadi express takes to cross a tree = 12 sec

Time August express takes to cross a tree = 12 sec

Formula used:

Speed = Distance/Time

Calculation:

We know that

 66.67% = (2/3)  

New time Shatabadi express takes to cross a tree = 12 × [(2 + 3)/3] = 20 sec

New time August express takes to cross a tree = 12 × [(100 + 150)/100] = 20 sec

⇒ New speed of Shatabadi express = 180/20 = 9 m/sec

⇒ New speed of August express = 240/30 = 8 m/sec

Required time = (180 + 240)/(9 + 8) = 420/17 = 24.7 sec

∴ Time taken by the two trains to cross each other is 24.7 sec