SOLUTION: Andrew can do a piece of work in r days and bill. who works faster, can do the same work in S days. which of the following expressions, if any, represents the number of days the tw

Question 479297: Andrew can do a piece of work in r days and bill. who works faster, can do the same work in S days. which of the following expressions, if any, represents the number of days the two of them would take to do the work if they worked together?
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
Andrew can do a piece of work in r days and bill. who works faster, can do the same work in S days. which of the following expressions, if any, represents the number of days the two of them would take to do the work if they worked together?
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Andrew rate: 1/r job/day
Bill rate::: 1/S job/day
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Together rate: (1/r)+(1/S) = [(S + r)/(rS)] job/day
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Together time: (rS)/(S+r) = days to do the job
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Cheers,
Stan H.
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