document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=734376>Question 734376</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 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? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #852719 by </B><A HREF=/tutors/aboutme.mpl?userid=greenestamps><B>greenestamps(13258)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=greenestamps><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=greenestamps><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=852719\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <br><BR>\n" );
document.write( "An informal solution, using logical reasoning instead of the formal algebra shown in the response from the other tutor....<br><BR>\n" );
document.write( "When the new sweeper joins the old one, the job is completed in 1/4 as much time (7.5 hours instead of 30), so it is as if there are now 4 of the old sweepers working.<br><BR>\n" );
document.write( "That means the new sweeper does as much work as 3 of the old sweepers.<br><BR>\n" );
document.write( "And since the old sweeper can do the job alone in 30 hours, the new sweeper can do the job alone is 1/3 as much time, which his 10 hours.<br><BR>\n" );
document.write( "ANSWER: 10 hours<br><BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );