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Working together, Evan and Ellie can do the garden chores in 6 hours. It takes Evan twice as long as Ellie to do the work alone. How many hours does it take Evan working alone?

 Jul 15, 2015

Best Answer 

 #2
avatar+128407 
+10

Let x be the time that Ellie takes to do the job alone......and Evan takes 2x....so we have

 

Then, the amount of work that Ellie does in one hour is 1/x   .....and the amount that Evan does is 1/(2x)

 

And ...Rate  x  Time   =   Amount of the job done......so......

 

6(1/x) + 6(1/(2x))  = 1    simplify

 

6/x +   3/x  = 1

 

9/x = 1       and x = 9  ....and this is the number of hours it takes Eliie to complete the job by herself

 

And 2(9)  = 18 hrs......and this is the time that Evan takes to do the job by himself  

 

 

  

 Jul 15, 2015
 #1
avatar
+1

a long time

 Jul 15, 2015
 #2
avatar+128407 
+10
Best Answer

Let x be the time that Ellie takes to do the job alone......and Evan takes 2x....so we have

 

Then, the amount of work that Ellie does in one hour is 1/x   .....and the amount that Evan does is 1/(2x)

 

And ...Rate  x  Time   =   Amount of the job done......so......

 

6(1/x) + 6(1/(2x))  = 1    simplify

 

6/x +   3/x  = 1

 

9/x = 1       and x = 9  ....and this is the number of hours it takes Eliie to complete the job by herself

 

And 2(9)  = 18 hrs......and this is the time that Evan takes to do the job by himself  

 

 

  

CPhill Jul 15, 2015

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