document.write( "Question 850681: A machine P can print one math book in 8 hours, machine Q can print the same number of books in 10 hours while machine R can print them in 12 hours. All the machines are started at 9 A.M. while machine P is closed at 11 A.M. and the remaining two machines complete work. Approximately at what time will the work (to print one math book) be finished ? \n" ); document.write( "
Algebra.Com's Answer #512308 by JulietG(1812)\"\" \"About 
You can put this solution on YOUR website!
We're assuming that the book can be made up of pieces.
\n" ); document.write( "P * 8 = 1
\n" ); document.write( "Q * 10 = 1
\n" ); document.write( "R * 12 = 1
\n" ); document.write( ".
\n" ); document.write( "or the inverse:
\n" ); document.write( "P = 1/8
\n" ); document.write( "Q = 1/10
\n" ); document.write( "R = 1/12
\n" ); document.write( ".
\n" ); document.write( "P prints 1/8 * 2 hours; 2/8 of a book.
\n" ); document.write( "In the same time, Q prints 2/10
\n" ); document.write( "In the same time, R prints 2/12
\n" ); document.write( ".
\n" ); document.write( "After 2 hours, 2/8 + 2/10 + 2/12 of a book is printed. (1/4 + 1/5 + 1/6)
\n" ); document.write( "Let's use a common denominator for 4,5,6 --> 60
\n" ); document.write( "After 2 hours, 15/60 + 12/60 + 10/60 is finished, or 37/60.
\n" ); document.write( ".
\n" ); document.write( "Each following hour,
\n" ); document.write( "Q prints 2/10 (or 12/60)
\n" ); document.write( "R prints 2/12 (or 10/60)
\n" ); document.write( ".
\n" ); document.write( "After 3 hours, 37/60 + 22/60 is finished. That is 59/60.
\n" ); document.write( ".
\n" ); document.write( "Since Q and R print 22/60 per hour (or at the rate of 2.728 minutes), the remaining 1/60 is printed at 12:02.728, or \"approximately\" 12:03 PM.
\n" ); document.write( ".
\n" ); document.write( "*sigh* This sounds like one of those horrible Common Core messes. \n" ); document.write( "
\n" );