T= time traveled
M= miles
So if he's traveled the speed limit, which is 75 miles per hour, then you'd multiply that by however long he drove. If he's driven the speed limit, that means he has or is going 75 miles an hour. Wherever he's going, he will be there in an hour if it's 75 miles away. So as a basis, you could use M(t), or 75 times Time. I think.
