The formula to use to calculate how fast a person is running is...
| SPEED OF RUNNER = | DISTANCE travelled by runner |
| TIME taken by runner |
If you want to know how long it will take a runner to cover a certain distance at a particular speed use...
| TIME TAKEN = | DISTANCE travelled by runner |
| SPEED of runner |
If you want to know how far a runner will go in a certain time when running at a particular speed use...
| DISTANCE = | SPEED of runner | x | TIME run for |