Kirk and Montega have accepted a job mowing the soccer playing fields. They must mow an area 500 feet long and 400 feet wide. They agree that each will mow half the area. They decide that Kirk will mow around the edge in a path of equal width until half the area is left.
To the nearest whole number, how many times should Kirk go around the field?
What is the width of the cut of Kirk's mower?
Total area = 400 * 500 = 200,000 ft^2
1/2 area = 100,000 sq ft
(400-2x) ( 500 - 2x) = 100000
200000 - 1800x + 2x^2 = 100000
4x^2 - 1800x + 100000 = 0
2x^2 -900x + 50000 = 0
x ≈ 385 ft (reject)
x ≈ 64.9 ft = 65 ft
He needs to make about 65/ 5 = 13 passes