SOLUTION: Martha can rake the leaves in her yard in 3 hours. Her younger brother can do the job in 5 hours. How long will it take them to the job if they work together?

Question 528593: Martha can rake the leaves in her yard in 3 hours. Her younger brother can do the job in 5 hours. How long will it take them to the job if they work together?
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
Martha can rake the leaves in her yard in 3 hours. Her younger brother can do the job in 5 hours. How long will it take them to the job if they work together?
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Martha rate = 1/3 job/hr
Brother rate = 1/5 job/hr
Together rate = 1/x job/hr
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Equation:
rate + rate = together rate
1/3 + 1/5 = 1/x
5x + 3x = 15
8x = 15
x = 15/8
x = 1 7/8 hrs = 1hr 53 minutes
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Cheers,
Stan H.
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