document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1159592>Question 1159592</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Please help me solve this word problem. \r<BR>\n" );
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document.write( "Suppose that coffee that is 155°F is poured into a coffee mug and allowed to cool in a room where the temperature is 65°F. The temperature T(in°F) of the coffee at time t ( in minutes) can be modeled by T(t) = 65 + 90e  -  0.045t <BR>\n" );
document.write( "According to the model when will the temperature of the coffee be 140°F? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #782714 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=782714\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 140=65+90e^(-0.045t)<BR>\n" );
document.write( "75=90e^(-0.045t)<BR>\n" );
document.write( "(75/90)=e^-0.045t=0.83333<BR>\n" );
document.write( "ln both sides to remove e<BR>\n" );
document.write( "-0.1823=-0.045 t<BR>\n" );
document.write( "t=4.05 minutes or about 4m3s </SPAN>\n" );
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