document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=861184>Question 861184</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The first term of an AP is 7, the last term is 77 and the sum is 380. Find the common difference in the series. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #518917 by </B><A HREF=/tutors/aboutme.mpl?userid=richwmiller><B>richwmiller(17219)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=richwmiller><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=richwmiller><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=518917\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> S = ½(a + an)n<BR>\n" );
document.write( "380= ½(7 + 77)n<BR>\n" );
document.write( "380= ½(84)n<BR>\n" );
document.write( "380=42n<BR>\n" );
document.write( "380/42=n<BR>\n" );
document.write( "190/21=n<BR>\n" );
document.write( "n = 9.0476<BR>\n" );
document.write( "not possible<BR>\n" );
document.write( "The number of terms is not a whole number\r<BR>\n" );
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document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );