document.write( "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? \n" ); document.write( "
Algebra.Com's Answer #293286 by stanbon(75887)\"\" \"About 
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?
\n" ); document.write( "-----------------
\n" ); document.write( "Jonathan rate: 1/40 job/min
\n" ); document.write( "Susan rate:: 1/30 job/min
\n" ); document.write( "Jack rate:: 1/24 job/min
\n" ); document.write( "Together rate:: 1/x job/min
\n" ); document.write( "-------------------------------
\n" ); document.write( "Equation:
\n" ); document.write( "rate + rate + rate = together rate
\n" ); document.write( "1/40 + 1/30 + 1/24 = 1/x
\n" ); document.write( "----
\n" ); document.write( "Multiply thru by 120x to get:
\n" ); document.write( "3x + 4x + 5x = 120
\n" ); document.write( "12x = 120
\n" ); document.write( "x = 10 minutes (time for them to do the job together)
\n" ); document.write( "=========
\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
\n" ); document.write( "========== \n" ); document.write( "
\n" );