Question 489288
Vanessa can do a job in 12 days. After she has worked for 4 days, she is joined by Susan, and they finish the job together in 2 more days.
 How long would it have taken Susan to do the whole job herself?
:
Let s = time required by Susan completing the job by herself
let the completed job = 1
:
From the given information we can see that V worked a total of 6 days, S worked 2 days
:
{{{6/12}}} + {{{2/s}}} = 1
multiply by 12s, results:
6s + 12(2) = 12s
24 = 12s - 6s
24 = 6s
s = 24/6
s = 4 days for Susan to do the job alone.