A 15-foot horizontal drain is set at 1/4 inch fall per foot. What total fall is required?
Correct Answer
A) 3.75 inches.
A quarter inch per foot for 15 feet gives 3.75 inches of fall.
Why This Is the Correct Answer
A quarter inch per foot for 15 feet gives 3.75 inches of fall.
Why the Other Options Are Wrong
Option B: 2.50 inches.
2.50 inches. is below the supported result for plumbing drainage slope; it likely omits allowance, conversion, coverage, or final round-up.
Option C: 5.00 inches.
5.00 inches. is above the supported result for plumbing drainage slope; it likely double-counts allowance, uses the wrong unit, or rounds too early.
Option D: 7.50 inches.
7.50 inches. is above the supported result for plumbing drainage slope; it likely double-counts allowance, uses the wrong unit, or rounds too early.
Memory Technique
Plumbing Drainage Slope cart for Checking Short: quarter first, inch second, whole the controlling choice last.
Reference Hint
Study anchor (closed-book): memorize Plumbing drainage slope from California Plumbing Code, California Code of Regulations Title 24. / Title 24 California Plumbing Code horizontal drainage slope; know the rule or calculation trigger without relying on exam-room lookup.
More Class B Trade Questions
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