SOLUTION: two printing presses working together can complete a job in 2.5hours.working alone,press A can do the job in 10 hours.How many hours will press B take to do the job by itself

Algebra ->  Customizable Word Problem Solvers  -> Age -> SOLUTION: two printing presses working together can complete a job in 2.5hours.working alone,press A can do the job in 10 hours.How many hours will press B take to do the job by itself      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


   



Question 628959: two printing presses working together can complete a job in 2.5hours.working alone,press A can do the job in 10 hours.How many hours will press B take to do the job by itself
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
two printing presses working together can complete a job in 2.5hours.working alone,press A can do the job in 10 hours.How many hours will press B take to do the job by itself
-------
together rate: 1/(5/2) = 2/5 job/hr
------
A machine rate: 1/10 job/hr
B machine rate: 1/x job/hr
--------------------------------
Equation:
rate + rate = together rate
1/x + 1/10 = 2/5
Multiply thru by 10x to get:
10 + x = 4x
3x = 10
x = 3 1/3 hrs (time for the B machine to do the job alone)
----------------
Cheers,
Stan H.
================