Question 928649
It takes Richard 39 minutes longer to do a job than it takes Katie to do the same job. Working together they can do the job in 40 minutes. How long will it take Richard and Katie to each do the job alone?
----
Together rate = 1/40 job/min
----
Katie rate = 1/x job/min
----
Richard rate = 1/(x+39) job/min
------
Equation:
rate + rate = together rate::
1/x + 1/(x+39) = 1/40
-------
40(x+39) + 40x = x(x+39)
----
40x + 40*39 + 40x = x^2 + 39x
----
x^2 -41x - 40*39 = 0
-----
x = 65 minutes (time for Katie to do the job)
x+39 = 104 minutes (time for Richard to do the job)
----------------------
Cheers,
Stan H.
================