So George's rate is 1 job per 60 days or= job(s)/day(s) Let Paul do 1 job in x days, then Paul's rate is 1 job per x days or = job(s)/day(s)
So together they can do 1 job in 20 days, so their combined rate is 1 job per 20 days or= job(s)/day(s) The equation comes from: + = + = Multiply through by LCD of 60x x + 60 = 3x -2x = -60 x = 30 So Paul will take 30 days to complete the same work if he works alone. Edwin