k, the time needed for Kirk working alone
PERSON RATE
Jeff 1/(k-3)
Kirk 1/k
Combined 1/10
The size of the wall 75 feet only represents the ONE JOB. How MUCH of the job is not emphasized in the description.
Solve for k, in .
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General solution for quadratic equation formula gives 21.6 hours for Kirk to do the one job by himself.