Mei can finish a task in 12 days and Joe can finish the same task in 6 days. Working together at their usual rates, how many days do they need?
Answer and explanation
Correct answer: A. 4 days
- Step 1: In one day Mei does and Joe does of the task.
- Step 2: Together: per day, so the task takes days.
Answer
4 days.
Why not the others: 9 days: the two times are averaged. 18 days: the two times are added. 6 days: the two times are subtracted.
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