SOLUTION: Susan can plant her garden in 5 hours working alone. A friend can do the same job in 8 hours? How long would t take them if they worked together? Thank you for your help.

Question 808858: Susan can plant her garden in 5 hours working alone. A friend can do the same job in 8 hours? How long would t take them if they worked together?
Thank you for your help.
Found 2 solutions by TimothyLamb, josmiceli:
Answer by TimothyLamb(4379) (Show Source): You can put this solution on YOUR website!
s = 5 hrs/garden
swr = 1/5 = 0.2 gardens/hour
f = 8 hrs/garden
fwr = 1/8 = 0.125 gardens/hour
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together:
1/5 + 1/8 = 13/40 gardens/hour
Answer, to do the garden together:
40/13 = 3.1 hours/garden
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Answer by josmiceli(19441) (Show Source): You can put this solution on YOUR website!
Add their rates of working to get their
rate working together
-------------------
Susan's rate:
( 1 garden planted ) / ( 5 hrs )
Friend's rate:
( 1 garden planted ) / ( 8 hrs )
--------------------------
Let = the time in hours to
plant a garden working together

Multiply both sides by

It will take them about 3 hrs 4.6 min

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