document.write( "Question 385919: Copier A can make 300 photocopies of a page in 15 minutes. Copier B can do the same job in 12 minutes. If both copiers work together, how long will it take them to do the same job? \n" ); document.write( "
Algebra.Com's Answer #280500 by lwsshak3(11628)\"\" \"About 
You can put this solution on YOUR website!
Copier A can make 300 photocopies of a page in 15 minutes. Copier B can do the same job in 12 minutes. If both copiers work together, how long will it take them to do the same job?\r
\n" ); document.write( "\n" ); document.write( "Let x = minutes it would take to do the job if both copiers work together.
\n" ); document.write( "1/x = work rate when both copiers work together
\n" ); document.write( "copy A can do the job in 15 minutes while working alone
\n" ); document.write( "copy A work rate =1/15
\n" ); document.write( "copy B can do the job in 12 minutes while working alone
\n" ); document.write( "copy B work rate =1/12
\n" ); document.write( "comparing hourly work rates
\n" ); document.write( "1/15+1/12=1/x
\n" ); document.write( "LCD=60
\n" ); document.write( "4+5=60/x
\n" ); document.write( "x=60/9 =6+2/3 minutes
\n" ); document.write( "ans: It would take 2 copiers working together 6+2/3 minutes to finish the same job\r
\n" ); document.write( "\n" ); document.write( "check:in 6+2/3 minutes, copier A makes( (6+2/3)/15)*300=133+1/3 copies
\n" ); document.write( " in 6+2/3 minutes, copier B makes (6+2/3)(12)*300=166+2/3 copies\r
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( " Note: The problem as given appears more complicated than it is. In setting up the equation to solve the problem, the number of copies to be made are not involved. In my experience, most of these working rate problems like this one can be solved by setting up an equation where the sum of the individual work rates are equal to the work rate when all individual work together. \n" ); document.write( "
\n" );