Worker A can complete a construction task in 12 days, while Worker B can complete the same task in 18 days. Working together, in how many days can they finish the task?
Answer and explanation
Correct answer: B. 7.2 days
- Step 1: Combined rate per day: 1/12 + 1/18 = (3 + 2) / 36 = 5/36 task per day. Step 2. Total days required: 36 / 5 = 7.2 days. Answer: 7.2 days. Why not the others: 6.0 days is half of 12; 8.0 days is an arbitrary guess; 7.5 days divides 15 by 2.
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