# Problems on Trains Questions

FACTS  AND  FORMULAE  FOR  PROBLEMS  ON  TRAINS

1. a km/hr = [a x (5/18)] m/s.

2. a m/s = [a x (18/5)] km/hr.

3. Time taken by a train of length l metres to pass a pole or a standing man or a signal post is equal to the time taken by the train to cover l metres.

4. Time taken by a train of length 1 metres to pass a stationary object of length b metres is the time taken by the train to cover (1 + b) metres.

5. Suppose two trains or two bodies are moving in the same direction at u m/s and v m/s, where u > v, then their relatives speed = (u - v) m/s.

6. Suppose two trains or two bodies are moving in opposite directions at u m/s and v m/s, then their relative speed = (u + v) m/s.

7. If two trains of length a metres and b metres are moving in opposite directions at u m/s and v m/s, then time taken by the trains to cross each other = $\frac{\left(a+b\right)}{\left(u+v\right)}$sec.

8. If two trains of length a metres and b metres are moving in the same direction at u m/s and v m/s, then the time taken by the faster train to cross the slower train = $\frac{\left(a+b\right)}{\left(u-v\right)}$sec.

9. If two trains (or bodies) start at the same time from points A and B towards each other and after crossing they take a and b sec in reaching B and A respectively, then (A's speed) : (B’s speed) = $\left(\sqrt{b}:\sqrt{a}\right)$

Q:

A train crosses a pole in 12 sec, and a bridge of length 170 m in 36 sec. Then the speed of the train is:

 A) 10.8 km/h B) 30.75 km/h C) 25.5 km/h D) 32.45 km/h

Explanation:

1 472
Q:

A train ]eaves from a station and moves at 40 km/hr. After 2 hours, another train leaves from the same station and moves in the same direction at a certain speed. lithe second train catches up with the first train in 4 hours, what is the speed of the second train?

 A) 55 km/hr B) 50 km/hr C) 60 km/hr D) 65 km/hr

Explanation:

0 421
Q:

A train without stoppage travels with an average speed of 72 km/h and with stop page ,it travels with an average speed of 60 km/h. For how many minutes does the train stop on an average per hour?

 A) 10 B) 6 C) 12 D) 8

Explanation:

2 416
Q:

The ratio between the speeds of two trains is 2 : 5. If the first train covers 350 km in 5 hours, then the speed (in km/h) of the second train is:

 A) 180 B) 175 C) 165 D) 150