Machine A can produce 100 units in 4 hours. Machine B can produce 100 units in 5 hours. If both machines work together, how many hours will it take them to produce 450 units?

A 8 hours

B 9 hours

C 10 hours

D 12 hours

✓ Correct Answer: Option C

Machine A's rate: 100 units / 4 hours = 25 units/hour. Machine B's rate: 100 units / 5 hours = 20 units/hour. Combined rate: 25 + 20 = 45 units/hour. To produce 450 units: 450 units / 45 units/hour = 10 hours.

💡 Why is C) the correct answer?

The correct answer to the question "Machine A can produce 100 units in 4 hours. Machine B can produce 100 units in 5 hours. If both machines work together, how many hours will it take them to produce 450 units?" is Option C: 10 hours.

The other options — A) 8 hours, B) 9 hours, D) 12 hours — are incorrect for this GRE Exam Prep question. As explained above: Machine A's rate: 100 units / 4 hours = 25 units/hour. Machine B's rate: 100 units / 5 hours = 20 units/hour. Combined rate: 25 + 20 = 45 units/hour. To produce 450 units: 450 units / 45 units/hour =…

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This 3-level GRE Exam Prep question from the Quantitative Reasoning topic is part of BrainForge Quiz's free exam preparation library. Each question includes the correct answer and a detailed explanation to help you understand the underlying concept, not just memorize the answer.

How to use this page: Read the question above, consider all four options (A through D), then check the highlighted correct answer and explanation. For active timed practice, start a free GRE Exam Prep practice test or use flashcards for spaced repetition review.

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Machine A can produce 100 units in 4 hours. Machine B can produce 100 units in 5 hours. If both machines work together, how many hours will it take them to produce 450 units?

✓ Correct Answer: Option C

📚 About This GRE Exam Prep Practice Question

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