document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=157424>Question 157424</A>: <I><SPAN STYLE=\"word-break: break-all;\"> a certain investment fund multiplies the value of an investment by 4 every year. Thus, after n years, the value of the investment is multiplied by 4^n. how many years will it take for the value of the investment to be multiplied by 256? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #116019 by </B><A HREF=/tutors/aboutme.mpl?userid=gonzo><B>gonzo(654)</B></A><img src=\"/images/stars/stars-11.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=gonzo><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=116019\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> n = 4<BR>\n" );
document.write( "4^4 = 256.<BR>\n" );
document.write( "n = 1, multiply by 4<BR>\n" );
document.write( "n = 2 multiply by 4 again = 16<BR>\n" );
document.write( "n = 3 multiply by 4 again = 64<BR>\n" );
document.write( "n = 4 multiply by 4 again = 256<BR>\n" );
document.write( "solved by using logarithms although n was so small it could have been done by simply working up each year as shown above.<BR>\n" );
document.write( "n = log of 256 to the base 4 is the same as n = log of 256 to the base 10 divided by log of 4 to the base 10.<BR>\n" );
document.write( "this allows the calculator to be used.<BR>\n" );
document.write( "log of 256 to the base 10 = 2.408........<BR>\n" );
document.write( "log of 4 to the base 10 = .602..................<BR>\n" );
document.write( "n = log of 256 to the base 10 / log of 4 to the base 10 = 4<BR>\n" );
document.write( "n = 4 </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );