ACT (Enhanced)MathematicsEasy
A construction crew is pouring a concrete slab for a patio. The slab is rectangular, with a length of 12 feet and a width of 8 feet. If the concrete is poured to a uniform depth of 0.5 feet, what is the volume of concrete needed?
- A100 cubic feet
- B48 cubic feet
- C20 cubic feet
- D96 cubic feet
Show answer & explanationAnswer & explanation
Correct answer: B. 48 cubic feet
The volume of a rectangular prism (slab) is calculated by multiplying its length, width, and height (depth). So, Volume = 12 ft * 8 ft * 0.5 ft = 96 * 0.5 = 48 cubic feet.
Why the other options are wrong
- A. This is an arbitrary incorrect calculation, possibly rounding up from C.
- C. This would be the perimeter multiplied by depth, or an incorrect sum.
- D. This would be the area (length × width) without multiplying by the depth, or multiplying by 1 instead of 0.5.
Volume of Rectangular Prism
The amount of three-dimensional space occupied by a rectangular prism, calculated by multiplying its length, width, and height.
- Units are always cubic (e.g., cubic feet, cubic meters).
- Applies to boxes, rooms, slabs, etc.
- Formula: V = l × w × h.
Memory trick: Box's Space: Length, Width, Height, Multiply!