document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=137388>Question 137388</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 1)On the first day of school, the percentage of boys in a particular class is 60%.  During the school year, six girls move away, and are replaced in the class by six boys; this makes the class roster 75% boys.  Find the number of boys and girls in the class on the first day of school.  \r<BR>\n" );
document.write( "<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "2)An express and local train leave GraysLake at 3 P.M. and head for Chicago 50 miles away. The express travels twice as fast as the local and arrives 1 hour ahead of the local. Find the speed of each train. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #100529 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=100529\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> On the first day of school, the percentage of boys in a particular class is 60%.<BR>\n" );
document.write( "During the school year, six girls move away, and are replaced in the class by six boys; this makes the class roster 75% boys.<BR>\n" );
document.write( "Find the number of boys and girls in the class on the first day of school. <BR>\n" );
document.write( "----------<BR>\n" );
document.write( "Original class numbers:<BR>\n" );
document.write( "Total = \"x\"<BR>\n" );
document.write( "Boys = 0.6x<BR>\n" );
document.write( "Girls= 0.4x<BR>\n" );
document.write( "------------------<BR>\n" );
document.write( "After 6-girls move and are replace by 6 boys:<BR>\n" );
document.write( "Total = \"x\"<BR>\n" );
document.write( "Boys:= 0.6x+6 = 0.75x\r<BR>\n" );
document.write( "\n" );
document.write( "--------------------------<BR>\n" );
document.write( "Boys equation shows:<BR>\n" );
document.write( "0.6x + 6 = 0.75x<BR>\n" );
document.write( "6 = 0.15x<BR>\n" );
document.write( "x = 40 (number in the class on the 1st day)<BR>\n" );
document.write( "-----------------\r<BR>\n" );
document.write( "\n" );
document.write( "2)An express and local train leave GraysLake at 3 P.M. and head for Chicago 50 miles away.<BR>\n" );
document.write( "The express travels twice as fast as the local and arrives 1 hour ahead of the local. Find the speed of each train.\r<BR>\n" );
document.write( "\n" );
document.write( "-----------<BR>\n" );
document.write( "Express DATA:<BR>\n" );
document.write( "Distance = 50 miles :  Rate = 2x mph ; time = 50/2x <BR>\n" );
document.write( "---------<BR>\n" );
document.write( "Local train DATA:<BR>\n" );
document.write( "Distance = 50 miles ; Rate = x mph ; time = 50/x<BR>\n" );
document.write( "-----------------<BR>\n" );
document.write( "EQUATION:<BR>\n" );
document.write( "local train time - express train time = 1 hr<BR>\n" );
document.write( "50/x - 50/2x = 1<BR>\n" );
document.write( "Multiply thru by 2x to get:<BR>\n" );
document.write( "100 - 50 = 2x<BR>\n" );
document.write( "50 = 2x<BR>\n" );
document.write( "x = 25 mph ( speed of the local train)<BR>\n" );
document.write( "2x = 50 mph ( speed of the express)<BR>\n" );
document.write( "=================<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );