One worker finishes a job in 10 days and another worker finishes it in 60 days. How long will they take if they work together?
Answer and explanation
Correct answer: D. 60/7 days
- Step 1: Their daily rates are 1/10 and 1/60, which add up to 70/600, so the time is 600/70 = 60/7 days. Answer: 60/7 days. Why not the others: 35 days: averages the two times. 70 days: adds the two times. 50 days: subtracts the times.
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