Time and Distance Formulas - Aptitude Questions and Answers

Speed

The speed of a moving body is the distance traveled by it in unit time.

Speed =

Distance travelled

Time taken

Distance = speed x time

Conversation of kmph to meter per second:

km/hr =

m/sec

m/sec =

km/hr

Relative speed:

If two bodies move in the same direction, the relative speed of one with respect to the other is the difference of their speeds.

If two bodies move in opposite direction, relative speed of one with respect to the other body is the sum of their speeds.

Important formulae:

If the ratio of the speeds of A and B is a : b, then the ratio of the

the times taken by them to cover the same distance is

or b : a

Suppose a man 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

2xy

x + y

km/hr.

Stoppage time per hour for a train:

For the same distance of travel, if a train runs at an average speed V₁km/hr without stopping and

an average speed of V₂km/hr with stoppage then stoppage time per hour =

V1 - V2

hour

Difference in speed

Faster speed

(hour)

Time and distance between two moving bodies:

Let there be two persons A and B

Speed of A = V₁km/hr

Speed of B = V₂km/hr

If they walk in the same direction, A and B will be (V₁ – V₂) km apart in 1 hour

Similarly, if they walk in opposite direction, A and B will be (V₁ + V₂) km apart in 1 hour