SOLUTION: please help me with this problem ): I have no idea where to begin and how to solve this. help! ): ):
Sarah can build a fence in 9 hours. Joe can do the same in 6 hours. How lon
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-> SOLUTION: please help me with this problem ): I have no idea where to begin and how to solve this. help! ): ):
Sarah can build a fence in 9 hours. Joe can do the same in 6 hours. How lon
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Question 760013: please help me with this problem ): I have no idea where to begin and how to solve this. help! ): ):
Sarah can build a fence in 9 hours. Joe can do the same in 6 hours. How long would it take them working together, to build the fence?
t=time together
1=the completed job
t/9=fraction of fence built by Sarah in t hours
t/6=fraction of fence built by Joe in t hours. Found 2 solutions by josgarithmetic, josmiceli:Answer by josgarithmetic(39615) (Show Source):
You can put this solution on YOUR website! Sarah's rate of working is:
( 1 fence built ) / ( 9 hours )
Joe's rate of working is:
( 1 fence built ) / ( 6 hours )
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If you add their rates of working, you get
their rate working together.
( Sarah's rate ) + ( Joe's rate ) = ( 1 fence built ) / ( t hours )
Notice that I want t hours to be the time to build 1 fence
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The equation is:
Multiply both sides by hrs
It will take them 3 hrs and 36 min working together
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t/9=fraction of fence built by Sarah in t hours
t/6=fraction of fence built by Joe in t hours.
You can arrive at this by multiplying both sides by
Time is now eliminated and the equation says:
( Sarah's part ) + ( Joe's part ) = 1 fence built
OK
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