SOLUTION: Jonathan can type a 20 page document in 40 minutes, susan can type it in 30 minutes, and Jack can type it in 24 minutes. Working together, how much time will it take them to type

Question 419350: Jonathan can type a 20 page document in 40 minutes, susan can type it in 30 minutes, and Jack can type it in 24 minutes. Working together, how much time will it take them to type the same document?
Found 2 solutions by stanbon, josmiceli:
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
Jonathan can type a 20 page document in 40 minutes, susan can type it in 30 minutes, and Jack can type it in 24 minutes. Working together, how much time will it take them to type the same document?
-----------------
Jonathan rate: 1/40 job/min
Susan rate:: 1/30 job/min
Jack rate:: 1/24 job/min
Together rate:: 1/x job/min
-------------------------------
Equation:
rate + rate + rate = together rate
1/40 + 1/30 + 1/24 = 1/x
----
Multiply thru by 120x to get:
3x + 4x + 5x = 120
12x = 120
x = 10 minutes (time for them to do the job together)
=========
Cheers,
Stan H.
==========
Answer by josmiceli(19441) (Show Source): You can put this solution on YOUR website!
Add their rates of typing
is Jonathan's rate ( 1 document/40 min)
is Susan's rate (1 document/30 min)
is Jack's rate (1 document/24 min)
------------------------------------
Let = the time in minutes with all 3 working together

Multiply both sides by

Multiply both sides by

It will take them 10 min working together
RELATED QUESTIONS
Jonathan can type a 20 page document in 40 minutes, Susan can type it in 30 minutes, and... (answered by richwmiller)
Jonathan can type a 20 page document in 40 minutes, Susan can type it in 30 minutes, and... (answered by Edwin McCravy)
Jonathan can type a 20 page in 40 minutes, Susan can type it in 30 minutes, and Jack can... (answered by scott8148)
Johnathan can type a 20 page document in 40 minutes. Susan can type it in 30 minutes, and (answered by Earlsdon)
john can type a 40, page document in 24 minutes, susan can type it in 30 minutes, jack... (answered by checkley77)
Three questions that I am certain have quite simple solutions but for some reason they... (answered by stanbon)
if jeanne can type 20 pages in 40 minutes and jim can type 20 pages in 30 minutes, how... (answered by Mathtut,ptaylor)
If Lynn can type a page in p minutes, what piece of the page can she type in 5 minutes? (answered by tutorcecilia)
If Lynn can type a page in p minutes, what piece of the page can she do in 5 minutes? (answered by )