<PRE><B>Question 1042097</B>
 Melanie takes four hours to wash a boat. It takes Jessica five hours to finish this job. How long would it take if they worked together? 
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Melanie rate:: 1/4 job/hr
Jessica rate:: 1/5 job/hr
Together rate: 1/x job/hr
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Equation:
rate + rate = together rate
1/4 + 1/5 = 1/x
5x + 4x = 5*4
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9x = 20
x = 20/9 = 2 2/9 hrs  = 2hr 13 min 20sec (time to do the job together)
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Cheers,
Stan H.
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