document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=990537>Question 990537</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The green neon lights flash every 5 seconds, the blue every 6 seconds and the red every 7 seconds. If all the lights flash together at 8:00 pm, (a) after how many seconds will they flash together again? (b) How many times will they flash together in one hour? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #610542 by </B><A HREF=/tutors/aboutme.mpl?userid=Boreal><B>Boreal(15235)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Boreal><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=Boreal><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=610542\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Greatest common denominator is 5*6*7=210 seconds.<BR>\n" );
document.write( "Half won't work, because 6 doesn't divide into 105.<BR>\n" );
document.write( "You need a number where 6*7 multiple ends in 5 or 0.  <BR>\n" );
document.write( "210 seconds is that multiple, or 8:03.30.<BR>\n" );
document.write( "3600/210=17.14, so 17 times in an hour. </SPAN>\n" );
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