SOLUTION: The HP Laser Jet 9000 works twice as fast as the Laser Jet 2300. If the machines work together, a university can produce all its staff manuals in 15hr. Find the time it would take

Algebra ->  Expressions-with-variables -> SOLUTION: The HP Laser Jet 9000 works twice as fast as the Laser Jet 2300. If the machines work together, a university can produce all its staff manuals in 15hr. Find the time it would take       Log On


   



Question 186736: The HP Laser Jet 9000 works twice as fast as the Laser Jet 2300. If the machines work together, a university can produce all its staff manuals in 15hr. Find the time it would take each machine, working alone, to complete the same job?
Answer by nerdybill(7384) About Me  (Show Source):
You can put this solution on YOUR website!
The HP Laser Jet 9000 works twice as fast as the Laser Jet 2300. If the machines work together, a university can produce all its staff manuals in 15hr. Find the time it would take each machine, working alone, to complete the same job?
.
Let x = speed of Laser Jet 2300
then
2x = speed of Laser Jet 9000
.
15(x + 2x) = 1
15x + 30x = 1
45x = 1
x = 1/45
the above says, completes a job in 45 hours (speed of Laser Jet 2300)
.
Laser Jet 9000:
2x = 2(1/45) = 2/45 = 1/22.5
the above says, completes a job in 22.5 hours (speed of Laser Jet 9000)
.