document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1150745>Question 1150745</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A laptop computer is purchased for $2600. Each year, its value is 80% of its value the year before. After how many years will the laptop computer be worth $900 or less? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #772164 by </B><A HREF=/tutors/aboutme.mpl?userid=Alan3354><B>Alan3354(69443)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Alan3354><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=Alan3354><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=772164\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A laptop computer is purchased for $2600. Each year, its value is 80% of its value the year before. After how many years will the laptop computer be worth $900 or less?\r<BR>\n" );
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document.write( "After 1 year, it's $2600*0.8 = $2080<BR>\n" );
document.write( "After 2 years, it's $2080*0.8 = $1664<BR>\n" );
document.write( "etc<BR>\n" );
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document.write( "FV = $2600*(0.8^t) --- t in years<BR>\n" );
document.write( "$900 = $2600*0.8^t<BR>\n" );
document.write( "9/26 = 0.8^t<BR>\n" );
document.write( "Log(9/26) = t*log(0.8)<BR>\n" );
document.write( "t = log(9/26)/log(0.8) = ~4.7542 years<BR>\n" );
document.write( "---> 5 years<BR>\n" );
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document.write( "Not a well stated problem.<BR>\n" );
document.write( "The answer can be \"after 10 years\" or after any # of years t > 4 (t as an integer).<BR>\n" );
document.write( "You can answer \"after 1000 years\" and not be wrong. </SPAN>\n" );
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