SOLUTION: Sam and Justin together can do a work in 2 days. If they had to work separately, the time taken by Justin to do the work would be more than that of Sam by 3 days. In how many days

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Question 1186013: Sam and Justin together can do a work in 2 days. If they had to work separately, the time taken by Justin to do the work would be more than that of Sam by 3 days. In how many days cam Justin do the work alone? (Applying quadratic equations)
Found 2 solutions by josgarithmetic, ikleyn:
Answer by josgarithmetic(39618)   (Show Source): You can put this solution on YOUR website!
              RATE             TIME in Days      JOBS

Sam             1/x               x                1

Justin          1/(x+3)           x+3              1

Together        1/2               2                1



Solving this will lead to a quadratic equation.
Answer by ikleyn(52793)   (Show Source): You can put this solution on YOUR website!
.
Sam and Justin together can do a work in 2 days.
If they had to work separately, the time taken by Justin to do the work would be more than that of Sam by 3 days.
In how many days cam Justin do the work alone? (Applying quadratic equations)
~~~~~~~~~~~~~~~~~~~~ 

Sam = x days

Justin = (x+3) days.


The combined rate equation is


     +  = .


The solution can be easily guessed MENTALLY:  x = 3 days.


ANSWER.  Sam can complete this job in 3 days, working alone.

         Justin can complete this job in 3+3 = 6 days, working alone.


CHECK.   +  =  =  =  = .    ! Correct !

Solved.

Alternatively,  you can reduce equation  (1)  to the standard quadratic equation form
and solve it formally  EITHER  using the quadratic formula  OR  by factoring.


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To see other similar solved problems, look into the lesson
    - Using quadratic equations to solve word problems on joint work
in this site.



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