document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1110473>Question 1110473</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Just this year Mira decided to invest a total of 20,000 in an account that earns 5.2% interest compounded continuously. Mira is now 20 years old. Set up an equation determining the total money in the account at any time t in years. In what year will the principal double (in value)? How old is Mira by then?  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #725450 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=725450\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> P=Poe^rt for continuous<BR>\n" );
document.write( "P=20000*e^(0.052t) ANSWER<BR>\n" );
document.write( "it will double in approximately 72/5.2 or about 14 years by rule of 72, which estimates it a little high.<BR>\n" );
document.write( "40000=20000e^.052t<BR>\n" );
document.write( "2=e^.052t<BR>\n" );
document.write( "ln 2=.052t<BR>\n" );
document.write( "0.693=0.052t<BR>\n" );
document.write( "t=13.33 years<BR>\n" );
document.write( "she will be 33 </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );