document.write( "Question 650788: With the old combine, Nikitas entire wheat crop can be harvested in 60 hours, but a new combine can do the same job in 20 hours. How many hours would it take to harvest the crop with both combines operating?
\n" ); document.write( " \n" ); document.write( "

Algebra.Com's Answer #407417 by ewatrrr(24785) $\"\"$ $\"About$

You can put this solution on YOUR website!

 
\n" );
document.write( "Hi,
\n" );
document.write( "old combine, crop can be harvested in 60 hours,
\n" );
document.write( "new combine can do the same job in 20 hours.
\n" );
document.write( "How many hours would it take to harvest the crop with both combines operating?
\n" );
document.write( "PER hour KEY
\n" );
document.write( " 1/60 + 1/20 = 1/x  |Multiplying thru by 60x so as all denominators = 1
\n" );
document.write( "  x  + 3x = 60
\n" );
document.write( "     4x = 60
\n" );
document.write( "      x = 15hrs it would take with both combines operating \n" );
document.write( "

\n" );