Civil Service Exam Reviewer · Ratio and Proportion · hard
9 workers working 8 hours a day can finish a project in 10 days. How many days will 4 workers working 6 hours a day need to finish the same project?
- 3.33 days
- 22.5 days
- 32 days
- 30 days
Answer
D. 30 days
Solution
Total work = 9 × 8 × 10 = 720 worker-hours. Days = 720 ÷ (4 × 6) = 30.
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