Problem Solving (PS) | Re: Audrey 4 hours to complete a certain job. Ferris can do the

Let total work be equal to 12 units
Efficiency of Audrey = 3 units per hour
Efficiency of Ferris = 4 units per hour
At his current work rate, Ferris was required to complete 8 units of the task in the two hours that they both spent on the task.
Similarly, Audrey is expected to complete 6 units of the task during the 2-hour duration.
Since Audrey actually spent all the 2 hours on the task, it implies that he actually completed 6 units. This implies that the remaining 6 units were completed by Ferris.
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