Question 701993
Two scientists are working on a special project. The experienced scientist can complete the project in 2 hours less than the other scientist. Together they were able to complete the job in 2.4 hours. How long would it take the experienced scientist to do the job alone?
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Experienced rate: 1/(x-2) job/hr
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Less-experienced rate: 1/x job/hr
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Together rate: 1/2.4 job/hr
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Equation:
rate + rate = together rate
1/x + 1/(x-2) = 1/2.4
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2.4(x-2) + 2.4x = x(x-2)
2.4x - 4.8 + 2.4x = x^2-2x
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x^2 - 6.8x + 4.8 = 0
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Usable solution : x = 6
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Answer: x-2 = 4 hrs (Time for the experienced scientist)
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Cheers,
Stan H.