337 and 1/2
Add 10% for breakage.
162
The perimeter of the patio is 24 feet.
225 square feet
A cubic yard of gravel will cover 81 square feet at 4" of thickness. Multiply the width of the patio by the length of the patio to get your square footage. Gravel is usually sold by the cubic yard.
54
To determine how many patio stones are needed, first convert the dimensions of one stone from inches to square feet. A 24-inch by 24-inch stone is 2 feet by 2 feet, giving it an area of 4 square feet. Dividing the total patio area of 480 square feet by the area of one stone (4 square feet) results in 120 stones needed for the patio.
12" x 12" = 1 square foot, so you need 452 of them.
12 x 12 blocks (assumed as 12 inch x 12 inch) That means the blocks are 1 square foot each Hence to cover 240 square feet area, you would need 240 blocks
8 feet
8 Feet
Assuming they are 8 inch*16 inch blocks, 144 square feet = 144*12*12 square inches. So number of blocks required = 144*12*12/(8*16) = 162
A square patio? if so, and one side is 8 ft. then it is 64 ft square