A slab is 30 feet long, 18 feet wide, and 4 inches thick. How many cubic yards of concrete are needed before waste?
Correct Answer
A) 6.67 cubic yards.
Convert 4 inches to one-third foot, calculate cubic feet, then divide by 27 cubic feet per cubic yard.
Why This Is the Correct Answer
Convert 4 inches to one-third foot, calculate cubic feet, then divide by 27 cubic feet per cubic yard.
Why the Other Options Are Wrong
Option B: 10.00 cubic yards.
10.00 cubic yards. is above the supported result for concrete quantity calculation; it likely double-counts allowance, uses the wrong unit, or rounds too early.
Option C: 18.00 cubic yards.
18.00 cubic yards. is above the supported result for concrete quantity calculation; it likely double-counts allowance, uses the wrong unit, or rounds too early.
Option D: 66.70 cubic yards.
66.70 cubic yards. is above the supported result for concrete quantity calculation; it likely double-counts allowance, uses the wrong unit, or rounds too early.
Memory Technique
Measure to convert, adjust for inches, then let Estimating Flatwork set the finish line.
Reference Hint
Study anchor (closed-book): memorize Concrete quantity calculation from 2025 California Building Code, California Code of Regulations Title 24 / Title 24 California Building Code concrete construction; quantity estimating practice; know the rule or calculation trigger without relying on exam-room lookup.
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