Area of pool = area of circle with a radius of 5 ft plus a 10 * 20 rectangle = pi*5^2 + 200 = 25pi + 200 = (1)
Total area = area of 10 * 30 rectangle = 300 = (2)
So....the probability that a golf ball DOES NOT land in the pool =
(2) - (1) [ 300 - ( 25 pi + 200 ) ] / 300 ≈ .0715 ≈ 7.2 %
______ =
(2)