document.write( "Question 734376: if a takes an old sweeper 30 hour to clean a street and takes a new and old sweepers together only 7.5 hours to clean the same street, then how long would it take for new sweeper to cleanse the same street? \n" ); document.write( "

Algebra.Com's Answer #852717 by ikleyn(53431) $\"\"$ $\"About$

You can put this solution on YOUR website!
.
\n" ); document.write( "if $\"highlight%28cross%28a%29%29\"$ it takes an old sweeper 30 hour to clean a street and takes a new and old sweepers together
\n" ); document.write( "only 7.5 hours to clean the same street, then how long would it take for new sweeper
\n" ); document.write( "to $\"highlight%28cross%28cleanse%29%29\"$ clean the same street?
\n" ); document.write( "~~~~~~~~~~~~~~~~~~~~~~~\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "

\r\n" );
document.write( "From the problem, the combined rate of the old and the new sweepers is    of the job\r\n" );
document.write( "per hour, when they work together,\r\n" );
document.write( "\r\n" );
document.write( "while the rate of the old sweeper is    of the job per hour.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "So, the rate of the new sweeper, when it works alone, is the difference\r\n" );
document.write( "\r\n" );
document.write( "     -  =  =  =  = \r\n" );
document.write( "\r\n" );
document.write( "of the job per hour.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "Hence, it will take 10 hours for the new sweeper to clean the street working alone.    ANSWER\r\n" );
document.write( "

\r
\n" ); document.write( "\n" ); document.write( "Solved.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "This method analyzing rate of work via fractions is very powerful and effective way solving such problems.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "

\n" );