For the patio (excluding sidewalk), if the slab is 4 inches thick, how many cubic yards of concrete are required?

For the patio (excluding sidewalk), if the slab is 4 inches thick, how many cubic yards of concrete are required?

• A. 5.60 cubic yards
• B. 5.75 cubic yards
• C. 5.50 cubic yards
• D. 5.90 cubic yards

Answer: (B)

The key idea is volume: concrete needed equals the patio area times the slab thickness, with the result expressed in cubic yards. First convert the thickness to feet: 4 inches is 4/12 = 1/3 ft. If you have the patio area in square feet, multiply by this thickness to get volume in cubic feet. Then convert to cubic yards by dividing by 27 (since 1 yd³ = 27 ft³). So the formula is V (yd³) = Area (ft²) × (1/3) ÷ 27 = Area ÷ 81. The correct option corresponds to an area of 465.75 ft², because 465.75 ÷ 81 = 5.75. In other words, a 4-inch-thick slab over 465.75 ft² requires about 5.75 cubic yards of concrete. If the area were 453.6 ft², you’d need 5.60 yd³; if it were 445.5 ft², you’d need 5.50 yd³, and so on. In practice, measure length × width to get area, convert thickness to feet, compute volume in cubic feet, then convert to cubic yards.

The key idea is volume: concrete needed equals the patio area times the slab thickness, with the result expressed in cubic yards.

First convert the thickness to feet: 4 inches is 4/12 = 1/3 ft. If you have the patio area in square feet, multiply by this thickness to get volume in cubic feet. Then convert to cubic yards by dividing by 27 (since 1 yd³ = 27 ft³). So the formula is V (yd³) = Area (ft²) × (1/3) ÷ 27 = Area ÷ 81.

The correct option corresponds to an area of 465.75 ft², because 465.75 ÷ 81 = 5.75. In other words, a 4-inch-thick slab over 465.75 ft² requires about 5.75 cubic yards of concrete. If the area were 453.6 ft², you’d need 5.60 yd³; if it were 445.5 ft², you’d need 5.50 yd³, and so on. In practice, measure length × width to get area, convert thickness to feet, compute volume in cubic feet, then convert to cubic yards.