Question 152192
A can do 1/10 of the job in one day.
B can do 1/8 of the job in one day.
.
1/10 + 1/8 + c = 1/3
12/120 + 15/120 + c = 40/120
c=40/12 - 27/120
=13/120 of the job in one day
So c can do the job in 120/13 days or 9 3/13 days.
.
Ed