bags of what?
There are approximately 27 cubic feet in a cubic yard, and an 80-pound bag of concrete typically yields about 0.6 cubic feet. Therefore, to fill one cubic yard, you would need about 45 bags of 80-pound concrete.
There are 27 cubic feet in a cubic yard, and a 60-pound bag of cement typically yields about 0.45 cubic feet when mixed. To fill one cubic yard, you would need approximately 60 bags of 60-pound cement.
One cubic yard is equivalent to 27 cubic feet. A 60-pound bag of Quikrete typically yields about 0.45 cubic feet of concrete. Therefore, to fill one cubic yard, you would need approximately 60 bags of 60-pound Quikrete bags (27 cubic feet ÷ 0.45 cubic feet per bag = 60 bags).
20
This cannot be answered without knowing the width and depth.
Forty five 80 pound bags of cement are needed to make one cubic yard of concrete.
You would need 31, 80 pound bags to cover 1 cubic yard at 4 inches deep. If you would like the depth to be 6 inches, 45 bags would be needed.
A typical 80-pound bag of concrete mix yields about 0.6 cubic feet of concrete. A 3-yard mixer has a capacity of 81 cubic feet (3 cubic yards). To fill the mixer, you would need approximately 135 bags of 80-pound concrete mix, since 81 cubic feet divided by 0.6 cubic feet per bag equals about 135 bags.
A standard bag of Quikrete typically weighs 80 pounds and covers about 0.6 cubic feet. Since there are 27 cubic feet in a cubic yard, you would need approximately 45 bags of 80-pound Quikrete to make one cubic yard. If using 60-pound bags, you would need about 60 bags for the same volume.
According to the FAQ on the Sakrete web site, Sixty of their sixty pound bags of High Strength concrete mix will be required to make a cubic yard of concrete.
According to the related link below; the required amount to cover 1 square yard with 4 inches of concrete is 6.6 60 pounds bags.
Depending on the use of the concrete, between 5-6 bags.