None, as a hole which is 6 inches wide and 42 inches long has no depth and thus no volume.
about 432 cubic inches
A hole with two dimensions has no third dimension. → its volume is 6 ft × 10 in × 0 ft = 0 ft³ → You require NO concrete to fill a hole which is given as an area as it has NO volume.
Depends on the length of the hole.
25 feet is equal to 300 inches. The radius of a hole is half its diameter, which equals 4 inches. The volume of the cylinder is given by the formula v = [Pi]r2h, so the volume of your hole is 3.14 * 16 * 300 = 15080 cubic inches. There are 1728 cubic inches to the cubic foot, so you'll need about 8.75 cubic feet of concrete, which is about a third of a yard. (More exactly, that's a cubic yard, but concrete guys just say "yard.")
2 inches = 1/6 foot27 cubic feet = 1 cubic yardVolume of the hole = (15' x 7' x 1/6-ft) = 17.5 cubic feet = 0.648 cubic yard (rounded)
about 432 cubic inches
18.6240 yd³
A hole with two dimensions has no third dimension. → its volume is 6 ft × 10 in × 0 ft = 0 ft³ → You require NO concrete to fill a hole which is given as an area as it has NO volume.
Depends on the length of the hole.
25 feet is equal to 300 inches. The radius of a hole is half its diameter, which equals 4 inches. The volume of the cylinder is given by the formula v = [Pi]r2h, so the volume of your hole is 3.14 * 16 * 300 = 15080 cubic inches. There are 1728 cubic inches to the cubic foot, so you'll need about 8.75 cubic feet of concrete, which is about a third of a yard. (More exactly, that's a cubic yard, but concrete guys just say "yard.")
17.5 cubic feet or about 3/4 of 1 cubic yard.
2 inches = 1/6 foot27 cubic feet = 1 cubic yardVolume of the hole = (15' x 7' x 1/6-ft) = 17.5 cubic feet = 0.648 cubic yard (rounded)
112 cuft
About 21 cubic feet
To determine the amount of concrete needed for a fence post installation, you should calculate the volume of the hole and then use a standard ratio of 1:2:3 (cement, sand, aggregate) to mix the concrete. Typically, a 50-pound bag of concrete mix will fill approximately 0.375 cubic feet. So, for example, if your hole is 2 feet deep and has a diameter of 8 inches, you would need about 0.25 cubic feet of concrete per post.
10-1/2 cubic yards
0.148 cubic yard for every 3-inches deep