document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=406295>Question 406295</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A man has four sons of different ages. Each of the older three sons is twice the age of the oldest of his younger brothers. The father's age is twice the age of his sons' ages. The sum of the father's and sons' age is 45. What is the oldest sons' age?  Stumped  Thank You for any help </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #286805 by </B><A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><B>ankor@dixie-net.com(22740)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><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=ankor@dixie-net.com><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=286805\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A man has four sons of different ages.<BR>\n" );
document.write( " Each of the older three sons is twice the age of the oldest of his younger brothers.<BR>\n" );
document.write( " The father's age is twice the age of his sons' ages. <BR>\n" );
document.write( "The sum of the father's and sons' age is 45.<BR>\n" );
document.write( " What is the oldest sons' age?<BR>\n" );
document.write( ":<BR>\n" );
document.write( "let f = father's age<BR>\n" );
document.write( "4 sons, a, b, c, d (a is oldest) <BR>\n" );
document.write( ":<BR>\n" );
document.write( "\" Each of the older three sons is twice the age of the oldest of his younger brothers\"<BR>\n" );
document.write( "a = 2b<BR>\n" );
document.write( "b = 2c<BR>\n" );
document.write( "c = 2d<BR>\n" );
document.write( ":<BR>\n" );
document.write( "\"The father's age is twice the age of his sons' ages.\"<BR>\n" );
document.write( "Let s = the sum of the sons' ages<BR>\n" );
document.write( "f = 2s<BR>\n" );
document.write( ":<BR>\n" );
document.write( "\"The sum of the father's and sons' age is 45.\"<BR>\n" );
document.write( "f + s  = 45<BR>\n" );
document.write( "f = 45 - s<BR>\n" );
document.write( "replace f with 2s<BR>\n" );
document.write( "2s = 45 - s<BR>\n" );
document.write( "2s + s = 45<BR>\n" );
document.write( "3s = 45<BR>\n" );
document.write( "s = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=45%2F3 ALIGN=MIDDLE  ALT=\"45%2F3\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "s = 15 yrs is the sum of sons' ages<BR>\n" );
document.write( "then<BR>\n" );
document.write( "f = 2(15)<BR>\n" );
document.write( "f = 30 yrs is father's age<BR>\n" );
document.write( ":<BR>\n" );
document.write( "\" What is the oldest sons' age?\"<BR>\n" );
document.write( "a + b + c + d = 15<BR>\n" );
document.write( "we know c = 2d, therefore<BR>\n" );
document.write( "a + b + 2d + d = 15<BR>\n" );
document.write( "we know b = 2c, therefore<BR>\n" );
document.write( "a + 4d + 2d = d = 15<BR>\n" );
document.write( "we know a = 2b, therefore<BR>\n" );
document.write( "8d + 4d + 2d + d = 15<BR>\n" );
document.write( "15d = 15<BR>\n" );
document.write( "d = 1 yrs is d's age<BR>\n" );
document.write( "and<BR>\n" );
document.write( "a = 8(1) the oldest son is 8 yrs old<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );