Fred wishes to enclose a square garden with wire whose sides measure 20 feet. If he decides to have the wire go around the garden five times, how much will the wire cost him if wire costs 40 cents for a spool of 50 feet?
The perimeter of the garden is 20 × 4 = 80 feet, so you would need 5 × 80 = 400 feet to go around it five times. Now, divide 400 feet by 50 feet and you get 8, which means that you need to buy 8 spools. Finally, 8 spools at 40 cents a spool would cost $3.20.