First, find the area of the table...
d = 4 ft ---> r = 2 ft
Area = 3.14 * (2 ft)² = 12.56 ft²
Find how many pads will cover the entire table. Since each pad is 1 ft²...
# of pads = 12.56 ft² / 1 ft² = 12.56
Find the total cost for all pads...
Total cost = 12.56 * $0.75 = $9.42