SOLUTION: Time off for lunch. It usually takes Eva 3 hours longer to do the monthly payroll than it takes Cicely. They start working on it together at 9:00 A.M. and at 5:00 P.M. they have

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Question 179308This question is from textbook
: Time off for lunch. It usually takes Eva 3 hours longer to
do the monthly payroll than it takes Cicely. They start
working on it together at 9:00 A.M. and at 5:00 P.M. they
have 90% of it done. If Eva took a 2-hour lunch break
while Cicely had none, then how much longer will it
take for them to finish the payroll working together? This question is from textbook

Answer by josmiceli(19441) (Show Source):
You can put this solution on YOUR website!
Let = the time it takes
Cicely to do monthly payroll
Then will be the time it takes
Eva to do the payroll
Let = the fraction of the 90% they
did working together
Let = the fraction of the 90% Cicely
did working 2 hrs by herself
given:
Between 9AM and 5 PM, there are 8 hrs
If Eva took a 2-hour lunch break, then she only
worked 6 hrs on the payroll.
They actually worked together for 6 hrs
and Cicely worked alone for 2 hrs.
---------------------------------
Working together:
(1)
(2)

(3)

--------------------
(1)

Multiply both sides by

Solve using quadratic formula

And,since
(3)

Also,since

Now I can solve for completing
the remaining 10% of the job
(1)

Multiply both sides by

hr

Working together, they can finish the job in 47.25 min
check:
(1)

close
(2)

OK