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 #449040 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
Let $\"+t+\"$ = time in hours for new sweeper to clean street
\n" ); document.write( "The new sweeper's rate of sweeping is ( 1 street cleaned ) / ( t hrs )
\n" ); document.write( "The old sweeper's rate of sweeping is ( 1 street cleaned / 30 hrs )
\n" ); document.write( "Together, their rate is ( 1 street cleaned ) / ( 7.5 hrs )
\n" ); document.write( "-------------
\n" ); document.write( "Add their rates of sweeping to get their rate sweeping together
\n" ); document.write( " $\"+1+%2F+30+%2B+1+%2F+t+=+1%2F+7.5+\"$
\n" ); document.write( "Multiply both sides by $\"+30t+\"$
\n" ); document.write( " $\"+t+%2B+30+=+4t+\"$
\n" ); document.write( " $\"+3t+=+30+\"$
\n" ); document.write( " $\"+t+=+10+\"$
\n" ); document.write( "It will take the new sweeper 10 hrs to clean street
\n" ); document.write( "check:
\n" ); document.write( " $\"+1%2F30+%2B+3%2F30+=+4%2F30+\"$
\n" ); document.write( " $\"+4%2F30+=+4%2F30+\"$
\n" ); document.write( "OK
\n" ); document.write( " \n" ); document.write( "

\n" );