Question 742664
Initially two painters are available to paint a picket fence. 
Peter alone could paint the fence in 6 hours; 
Paul alone in 3 hours.
Equation: 1/6 + 1/3 = 1/x
x + 2x = 6
3x = 6
x = 2 hrs (Time for Peter and Paul to do the job together)
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It is decided that they will work simultaneously to paint the fence. Before they start, however, along comes Mary, who alone could paint the fence in 8 hours.
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Your task is to determine exactly how many minutes could be saved if all 3 painters work together on the fence, as compared to only Peter and Paul doing the job in tandem.
1/6 + 1/3 + 1/8 = 1/x
4x + 8x + 3x = 24
15x = 24
x = 8/5 hrs (time for all three to do the job alone)
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Time saved: 2-(8/5) = (10/5)-(8/5) = 2/5 hrs = 24 minutes
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Determine how many additional minutes would be saved (beyond those found above) if Mary were able to paint the fence alone in 6 hours instead of 8 hours?
Comment: I'll leave that to you.
Cheers,
Stan H.
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