If they work together, Alex and his daughter can clear the entire yard in four hours. Given that Alex works twice as quickly as his daughter, how many hours would it take for his daughter to clear the entire yard by herself?

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Official Explanation

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Let A be the time it takes Alex to complete the job and D be the time it takes his daughter. We know that A + D = 1/4 and A = 2D. Substituting A into the equation gives us 2*D + D = 1/4. This simplifies to 3*D = 1/4, leading to D = 1/12.…

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Comments

MohamedJan 5, 2025

thank you very much!

What this question tests

What it tests

Your ability to combine individual work rates, usually by working with the fraction of a job completed per unit of time.

Common trap

Adding the times instead of the rates, or forgetting to take the reciprocal when combining rates.