FORMULAE FOR TRAIN QUESTIONS IN TIME AND DISTANCE

1. TIME TAKEN TO CROSS A POLE OR A MAN

= LENGTH OF A TRAIN / SPEED OF A TRAIN

2. TIME TAKEN TO CROSS A PLATFORM

 = LENGTH OF (TRAIN + PLATFORM) / SPEED OF TRAIN

3. TIME TAKEN TO CROSS A BRIDGE

 = LENGTH OF (TRAIN + BRIDGE) / SPEED OF TRAIN

4. WHEN 2 TRAINS MOVE TOWARDS EACH OTHER THEN, TIME TAKEN TO CROSS EACH OTHER

= SUM OF LENGHTHS OF BOTH TRAINS / SUM OF THEIR SPEEDS

5. WHEN 2 TRAINS ARE MOVING IN THE SAME DIRECTION THEN, TIME TAKEN TO CROSS EACH OTHER

= SUM OF LENGTHS OF BOTH TRAINS / DIFFERENCE OF THEIR SPEEDS

6. WHEN 2 TRAINS ARE MOVING AT SPEED OF x km/hr AND y km/hr 

(i) RELATIVE SPEED WHEN MOVING TOWARDS EACH OTHER=(x+y) km/hr

(ii) RELATIVE SPEED WHEN MOVING IN THE SAME DIRECTION=(x-y) km/hr WHERE x>y

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