document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=288305>Question 288305</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I noticed that when I interchanged the digits of my father’s age, I got my own age. When I was born, his age was between twenty and thirty years. What was my father’s age when I was born?<BR>\n" );
document.write( "(A) 20 (B) 26 (C) 27 (D) 30 (E) None of these </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #208968 by </B><A HREF=/tutors/aboutme.mpl?userid=richwmiller><B>richwmiller(17219)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=richwmiller><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=richwmiller><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=208968\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> f=10a+b,<BR>\n" );
document.write( "s=10b+a,<BR>\n" );
document.write( "20<=f-s<=30<BR>\n" );
document.write( "20 and 30 are not between 20 and 30<BR>\n" );
document.write( "so it must be 26 or 27<BR>\n" );
document.write( "It is 27.<BR>\n" );
document.write( "a = 9-n,   b = 6-n,   f = 96-11 n,   s = 69-11 n,   n element Z,   n>=0<BR>\n" );
document.write( "let n=1<BR>\n" );
document.write( "a=8; b=5<BR>\n" );
document.write( "possible ages for father and son<BR>\n" );
document.write( "85-58=27<BR>\n" );
document.write( "96-69=27<BR>\n" );
document.write( "74-47=27<BR>\n" );
document.write( "63-36=27<BR>\n" );
document.write( "52-25=27<BR>\n" );
document.write( "41-14=27<BR>\n" );
document.write( "30-3=27\r<BR>\n" );
document.write( "\n" );
document.write( "b=a-3<BR>\n" );
document.write( "f=11a-3<BR>\n" );
document.write( "s=11a-30<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );