SOLUTION: worker A can do a certain job in 12 hours.Worker B can do the same job in 9 hours.How long would it take if they worked together?

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: worker A can do a certain job in 12 hours.Worker B can do the same job in 9 hours.How long would it take if they worked together?      Log On


   

Question 259415: worker A can do a certain job in 12 hours.Worker B can do the same job in 9 hours.How long would it take if they worked together?
Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
(x / 12) + (x / 9) = 1

3x + 4x = 36

x = 36/7 (a bit over 5 hours)