document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1059614>Question 1059614</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A local civic theater has 22 seats in the first row and 21 rows in all. Each successive row contains 3 additional seats. How many seats are in the civic theater?<BR>\n" );
document.write( "a.) 1092<BR>\n" );
document.write( "b.) 1010 <BR>\n" );
document.write( "c.) 1070<BR>\n" );
document.write( "d.) 790 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #674663 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=674663\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> sum of the 21 rows, s21=21/2(22+sn), where the last row, 20th back, has 60 more seats or 82.<BR>\n" );
document.write( "Therefore, s21=21/2(22+82)=21/2(104)=1092 seats. The formula takes the first and the last and uses that as an average, multiplying by the number of rows.<BR>\n" );
document.write( "22+25+28+31=116<BR>\n" );
document.write( "34+37+40+43=154<BR>\n" );
document.write( "46+49+52+55=202<BR>\n" );
document.write( "58+61+64+67=250<BR>\n" );
document.write( "70+73+76+79=298<BR>\n" );
document.write( "82==========82<BR>\n" );
document.write( "That equals 1092. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );