SOLUTION: Write an expression for the sum of the work rates: Cary and a friend apply one coat of paint in a room in 2.5 hours. Cary's friend paints twice as fast as Cary when they paint se

Question 753358: Write an expression for the sum of the work rates:
Cary and a friend apply one coat of paint in a room in 2.5 hours. Cary's friend paints twice as fast as Cary when they paint separately.
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
Cary and a friend apply one coat of paint in a room in 2.5 hours. Cary's friend paints twice as fast as Cary when they paint separately.
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Together: time = 2.5 hrs/job ; rate = 1/2.5 = 2/5 job/hr
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Cary's friend: time = x hr/job ; rate = 1/x job/hr
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Cary: time = 2x hr/job ; rate = 1/2x job/hr
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Equation:
rate + rate = together rate:
1/x + 1/(2x) = 2/5
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Cheers,
Stan H.
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