document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=772096>Question 772096</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The number of bacteria in a culture is given by b(t) = 1400e^0.25t, where t is measured in hours. After how many hours will the number of bacteria in the culture be three times that of the initial number of bacteria? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #470679 by </B><A HREF=/tutors/aboutme.mpl?userid=Cromlix><B>Cromlix(4381)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Cromlix><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=Cromlix><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=470679\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\">  b(t) = 1400e^0.25t,<BR>\n" );
document.write( "At t = 0 the number of bacteria<BR>\n" );
document.write( "will be = 1400<BR>\n" );
document.write( "3 * 1400 = 4200<BR>\n" );
document.write( " b(t) = 1400e^0.25t,<BR>\n" );
document.write( "4200 = 1400 e^0.25t<BR>\n" );
document.write( "4200/1400 = e^0.25t<BR>\n" );
document.write( "3 = e^0.25t<BR>\n" );
document.write( "loge 3 = 0.25t loge e (loge e = 1)<BR>\n" );
document.write( "t = loge 3/0.25<BR>\n" );
document.write( "t = 4.39 hours<BR>\n" );
document.write( "t = 4hrs 23mins.<BR>\n" );
document.write( "Hope this helps.<BR>\n" );
document.write( ":-) </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );