SOLUTION: Andrew takes eighteen hours to complete a certain project alone. he had worked six hours on the project when Dylan joined him to finish the project. Together they finished the proj

Algebra ->  Rate-of-work-word-problems -> SOLUTION: Andrew takes eighteen hours to complete a certain project alone. he had worked six hours on the project when Dylan joined him to finish the project. Together they finished the proj      Log On


   



Question 218910: Andrew takes eighteen hours to complete a certain project alone. he had worked six hours on the project when Dylan joined him to finish the project. Together they finished the project in six more hours. How many hours does it take for Dylan to complete the entire project alone?
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
Andrew takes eighteen hours to complete a certain project alone.
he had worked six hours on the project when Dylan joined him to finish the project.
Together they finished the project in six more hours.
How many hours does it take for Dylan to complete the entire project alone?
:
Let t = time required by Dylan alone
:
Let the completed job = 1
:
Andrew will work a total of 12 hrs
:
12%2F18 + 6%2Ft = 1
Multiply equation by 18t, results:
12t + 18(6) = 18t
12t + 108 = 18t
108 = 18t - 12t
108 = 6t
t = 108%2F6
t = 18 hrs is D's time alone also