Vaughn paints his porch floor and also the porch floors of 9 neighbors. Each floor is a rectangle that is 8.2 feet long and 6.7 feet wide.

First, we have to calculate the area of each painted rectangle:
Area of a rectangle: Length x width
Replacing with the values given:
8.2 x 6.7 = 54.94 ft2
Estimating:
8 x 7 = 56 ft2
Then multiply by the number of porch floors:
9 neighbor's floors and Vaughn's floor = 9+1 = 10
56 x 10 = 560 ft2
correct answer B.