If you go 70mph for one hour….you’ll go 70 miles.

If you go 70mph for two hours….you’ll go 140 miles.

If you go 70mph for half an hour…. you’ll go 35 miles.

The rule is:

rate * time = distance

In my algebra book sometimes they mix it up.

Sometimes they give the distance and the rate and have to solve for time.

Sometimes they give the distance and the time and have to solve for rate.

That is easy:

rate = distance / time

time = distance / rate

Another thing they want me to do is to find the average speed:

average speed = total distance / total time