Two trains leave New Delhi at the same time. One travels north at 60 kmph and the other travels south at 40 kmph. After how many hours will the trains be 150 km apart ?

examrobotsa's picture

Submitted by examrobotsa on

Q: 27 (IAS/2010)
Two trains leave New Delhi at the same time. One travels north at 60 kmph and the other travels south at 40 kmph. After how many hours will the trains be 150 km apart ?

question_subject: 

Maths

question_exam: 

IAS

stats: 

0,17,13,17,7,4,2

keywords: 

{'new delhi': [1, 0, 1, 2], 'km': [0, 0, 2, 1], 'trains': [0, 0, 2, 0], 'many hours': [0, 0, 3, 1]}

We can solve this problem using the formula:

distance = speed x time

Let`s assume that the two trains start at time t=0.

After t hours, the distance traveled by the northbound train is 60t km.

Similarly, the distance traveled by the southbound train is 40t km.

The distance between them is the sum of these distances, which is:

distance = 60t + 40t = 100t km

We want the distance to be 150 km. So we set up the equation:

100t = 150

Solving for t, we get:

t = 1.5 hours

Therefore, the two trains will be 150 km apart after 1.5 hours.

So, the answer is option (a) 3/2.