SOLUTION: Tom can do a job in 3 hours, Dick in 4 hours, and Harry in 6 hours. If they do it together (and do not delay each other), how long does the job take?

Algebra ->  Rate-of-work-word-problems -> SOLUTION: Tom can do a job in 3 hours, Dick in 4 hours, and Harry in 6 hours. If they do it together (and do not delay each other), how long does the job take?      Log On


   



Question 130566: Tom can do a job in 3 hours, Dick in 4 hours, and Harry in 6 hours. If they do it together (and do not delay each other), how long does the job take?
Answer by ptaylor(2198) About Me  (Show Source):
You can put this solution on YOUR website!
Let x=amount of time it take all three working together to do the job
Now we know that:
Tom works at the rate of 1/3 job per hour
Dick works at the rate of 1/4 job per hour
Harry works at the rate of 1/6 job per hour
Together they work at the rate of 1/3 +1/4 +1/6 job per hour or
8/24 + 6/24 +4/24=18/24=3/4 job per hr
Now our equation to solve is:
(3/4)*x=1 (1 job, that is) multiply both sides by 4
3x=4
x=1 1/3 hours ---amount of time it takes all three working together
Hope this helps---ptaylor