SOLUTION: Aira can do a job in 4 hours and Queenie can do the same in 9 hours. They start working together. After 2 hours, Queenie leaves and Aira finishes the job alone. How many hours did

Question 982505: Aira can do a job in 4 hours and Queenie can do the same in 9 hours. They start working together. After 2 hours, Queenie leaves and Aira finishes the job alone. How many hours did Aira take to finish the job alone?
Answer by josmiceli(19441) (Show Source): You can put this solution on YOUR website!
Let = the fraction of the job they
do working together for 2 hrs
Aira's rate of working is:
[ 1 job done / 4 hrs ]
Queenie's rate of working is:
[ 1 job done / 9 hrs ]
----------------------------
Add their rates of working to get
their rate working together
Their rate working together is:

Multiply both sides by

In 2 hrs, they do of the work. That
means there is
of the work left to do
-------------------------
Let = time in hrs for Aira to
finish the job

Multiply both sides by

---------------------
Aira finishes the job in 1 hr 6 min 40 sec
check answer:

OK
Hope I got it!

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