If a person can walk 3 miles in one hour, how far from school are they if it takes 20 minutes to walk to school. I have the answer by using common sense but I need to know the formula for calculating distance as it relates to this question. Further I do not know how to break down the info given by using a formula. If I say that D = V x t and then say D = 3 miles per hour x 20 minutes = 60 but I know the answer is one mile. What do I need to do in order to show my calculations correctly?

Distance = Speed x Time

You need your units to be the same, if you're using miles per hour then you need to convert your time into hours. (or your speed into miles per minute)

And the speed you mentioned above is 3 miles per hour. Using the equation of Curlyben, D is distance and not speed. If you had put it right above, then you'd have obtained the right answer.

It's a in the units.

D=Speed x Time; If Speeds is in mph then time must be in hours.

D=S(mi/h) x h; the hours cancel and you end up with S miles

The number multiplication is part of it. You need to make sure the units are correct too.

Just like what is the answer in cuft for a plot that's 6'10" x 4'3" x 2" deep