document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1204442>Question 1204442</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Find the number of terms in an A.P, whose first term is 1, last term is 77 and the sum of terms is 507 </SPAN>\n" );
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document.write( "n = number of terms\r<BR>\n" );
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document.write( "Sn = sum of first n terms of arithmetic progression (AP)<BR>\n" );
document.write( "Sn = (n/2)*(first term + nth term)<BR>\n" );
document.write( "507 = (n/2)*(1 + 77)<BR>\n" );
document.write( "507*2 = 78n<BR>\n" );
document.write( "1014 = 78n<BR>\n" );
document.write( "n = 1014/78<BR>\n" );
document.write( "n = 13\r<BR>\n" );
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document.write( "Answer: <font color=red>13 terms</font><BR>\n" );
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