Question

A cross country runner runs 100 km in 80 minutes. What is his average speed?

Answer 1

Divide the distance (`d`) by time taken.

Explanation:

Use the equation

`d=rt`

where distance (`d`) is equal to the product of rate (`r`) and time (`t`).

Now, the distance and time are given. So we have to rearrange the equation to solve for `r`:

`d=rt`

`((d))/t=((rt))/t`

`r=d/t`

Now, let's plug in the values we have been given to find the rate:

`r=d/t`

`r=(100" km")/(80 " min")`

`r=1.25 " km/min"`

I hope that helps!

P.S. One thing to note is, as the original contributor mentioned, this model is not realistic, as it is impossible for a human to run this fast in real life.