# How to solve train puzzle problems easily-Important formula to watch -Updated on November 13, 2011-Find more at Aptitude,Problems on Trains

When we come to an interview ie written puzzle or aptitude test, Problems on trains going to be a most difficult to solve and also when solving train related puzzles it took lots of time to get the answer.

Here are the tips and points to remember to solve train problems easily and important formula to watch.

Tip 1: The formula to convert KMPH to MPS and vice versa.

** km/hr to m/s conversion: y km/hr =y*(5/18)m/s**

** m/s to km/hr conversion: y m/s = y*(18/5)km/hr**

Tip 2: Time taken by a train of length *l* metres to pass a stationery object of length *b* metres is the time taken by the train to cover (*l* + *b*) metres.

Tip 3: Time taken by a train of length *l* metres to pass a pole or standing man or a signal post = time taken by the train to cover *l* metres.

Tip 4: Two trains or two objects bodies are moving in the same direction at u m/s and v m/s, where u > v, then their relative speed is =** (u – v) m/s.**

Tip 5: Suppose two trains or two objects bodies are moving in opposite directions at *u* m/s and *v* m/s, then their relative speed is = **(u + v) m/s.**

Tip 6: If two trains of length *a* metres and *b* metres are moving in opposite directions at *u* m/s and *v* m/s, then the time taken by the trains to cross each other = *(a + b)/ (u + v) sec*

Tip 7: 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 = * (a + b)/ (u – v) sec*

Tip 8: If two trains (or any bodies) start at the same time from points A and B towards each other and after crossing they take x and y sec in reaching B and A respectively,

** (A’s speed) : (B’s speed) = (y : x)**

Tip 9: If a train or a body covers a certain distance at *x* km/hr and an equal distance at *y* km/hr. Then, the average speed during the whole journey is **2 xy /(x + y) km/hr**.

The above formulas are guided to solve train and time taken problems in aptitude solutions.

## Add comments

it is so easy to remind all things in short duration.

Boring ideas I knew them from beginning

Usefull notes but i need some example