To find the length of the floor of the rectangular deck, you can use the formula for the area of a rectangle, which is:
Area = Length x Width
Given that the area is 600 square feet and the width is 20 feet, you can substitute these values into the formula:
600 = Length x 20
To find the length, you need to divide the area by the width:
Length = Area / Width
Length = 600 / 20
Length = 30 ft
Therefore, the length of the floor of the rectangular deck is 30 feet. So, the correct answer is C. 30 ft.
