A carpentry crew's base productivity is 120 sq ft of framing per hour. Working at 15 feet above grade reduces productivity by 10%, and working in 25°F weather reduces it by another 15%. What is the adjusted hourly productivity?
Correct Answer
A) 91.8 sq ft/hour
Base productivity = 120 sq ft/hr. Height factor = 0.90 (10% reduction). Weather factor = 0.85 (15% reduction). Adjusted productivity = 120 × 0.90 × 0.85 = 91.8 sq ft/hour.
Why This Is the Correct Answer
Option A correctly applies compound productivity reductions. Starting with 120 sq ft/hr base productivity, the 10% height reduction gives a factor of 0.90, and the 15% weather reduction gives a factor of 0.85. These factors multiply together: 120 × 0.90 × 0.85 = 91.8 sq ft/hour. Both reductions compound, meaning each affects the already-reduced productivity.
Why the Other Options Are Wrong
Option B: 108.0 sq ft/hour
This answer incorrectly applies only the 10% height reduction (120 × 0.90 = 108), completely ignoring the additional 15% weather reduction. In real construction scenarios, multiple adverse conditions compound their effects on productivity, so both factors must be applied sequentially.
Option C: 95.4 sq ft/hour
This represents applying the reductions additively rather than multiplicatively. Adding the percentages (10% + 15% = 25% total reduction) gives 120 × 0.75 = 90, but this doesn't account for how productivity factors actually compound in construction work.
Option D: 102.0 sq ft/hour
This answer incorrectly applies only the 15% weather reduction (120 × 0.85 = 102), completely ignoring the 10% height reduction factor. Both adverse conditions affect the crew simultaneously and must both be factored into the productivity calculation.
Memory Technique
Remember 'MULTIPLY for MULTIPLE troubles' - when facing multiple adverse conditions, multiply the remaining productivity factors (0.90 × 0.85) rather than adding the reduction percentages.
More NASCLA Questions
Which AIA document contains the general conditions that govern the rights and responsibilities of all parties in a construction contract?
A construction company has direct labor costs of $85,000, direct materials of $120,000, and overhead costs of $45,000 for a project. What is the total job cost?
What is the primary purpose of job cost accounting in construction?
A construction company has current assets of $350,000 and current liabilities of $280,000. What is the company's working capital?
In CSI MasterFormat, which division covers earthwork and site preparation?
In a mechanical drawing, what does 'CFM' typically measure?
In CSI MasterFormat Division 08, which of the following would typically be included?
On a mechanical plan, what does the symbol 'RTU' typically indicate?
What is the minimum preheat temperature for welding ASTM A992 steel when the ambient temperature is 15°F?
A general contractor's balance sheet shows total assets of $850,000, current liabilities of $320,000, and long-term debt of $180,000. What is the company's equity?
People Also Study
Business & Financial Management
120 questions · 70% to pass
Contract Administration
60 questions · 70% to pass
Project Management
60 questions · 70% to pass
Related Study Resources
Previous Question
When estimating material costs, which factor is MOST important to consider for price accuracy?
Next Question
A contractor needs a crane for 6 weeks. The rental cost is $1,800 per week plus $150 per day for an operator. If purchasing, the crane costs $85,000 with $12,000 annual maintenance and a 10-year depreciation. The operator cost remains the same. Assuming 5 working days per week, what is the cost difference between renting and the allocated purchase cost?