SOLUTION: It usually takes Eva 3 hours longer to do the monthly payroll than it takes Cindy. They start working on it together at 9.00 AM and at 5.00 PM they have 90% of it done. If Eva took

Question 210858: It usually takes Eva 3 hours longer to do the monthly payroll than it takes Cindy. They start working on it together at 9.00 AM and at 5.00 PM they have 90% of it done. If Eva took s 2 hour lunch break while Cindy had none, then how much longer will it take for them to finish the payroll working together?
Answer by josmiceli(19441) (Show Source): You can put this solution on YOUR website!
(Cindt's rate) + (Eva's rate) = Rate working together
actually they worked together for 6 of the 8 hours
and Cindy worked 2 hours alone
Let = hours it takes Cindy to finish 1 payroll
= hours for Eva to finish 1 payroll
Let = fraction of payroll completed in 6 hours
with both working together

And Cindy working alone for 2 hours:

and

Multiply both sides by

Use quadratic equation

hrs
They have 10% of the job left

hrs
It will take them about 47.3 min to finish the job
(Unless I goofed)

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