## Unit Conversion – kmph ⇔ mps

## Shortcut Formulas for Time and Distance

**Rule 1:** If some distance is travelled at x km/hr and the same distance is travelled at y km/hr then the average speed during the whole journey is given by

**Rule 2: **If a person travels a certain distance at x km/hr and returns at y km/hr, if the time taken to the whole journey is T hours then the one way distance is given by

**Rule 3: **If two persons A and B start their journey at the same time from two points P and Q towards each other and after crossing each other they take a and b hours in reaching Q and P respectively, then

**Rule 4:** If the same distance is covered at two different speeds S_{1} and S_{2} and the time taken to cover the distance are T_{1} and T_{2}, then the distance is given by