document.write( "Question 1179861: A man is able to save #50 of his salary in a particular year ,after this,every year he saved #20 more than the preceeding year .how long does it take him to save #4370 \n" ); document.write( "
Algebra.Com's Answer #809434 by mananth(16946)\"\" \"About 
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\n" ); document.write( "A man is able to save #50 of his salary in a particular year ,after this,every year he saved #20 more than the preceeding year .how long does it take him to save #4370\r
\n" ); document.write( "\n" ); document.write( "First year 50
\n" ); document.write( "seond year 70
\n" ); document.write( "third year 90\r
\n" ); document.write( "\n" ); document.write( "time = n = ?\r
\n" ); document.write( "\n" ); document.write( "Sn = 4370\r
\n" ); document.write( "\n" ); document.write( "Sn= [ (n/2)(2a+(n-1)d)]\r
\n" ); document.write( "\n" ); document.write( "4370 = n/2[ 2*50 + (n-1)*20]\r
\n" ); document.write( "\n" ); document.write( "8740= n(100+20n-20)\r
\n" ); document.write( "\n" ); document.write( "8740 = n(80+20n)\r
\n" ); document.write( "\n" ); document.write( "8740 = 80n +20n^2\r
\n" ); document.write( "\n" ); document.write( "20n^2+80n-8740=0\r
\n" ); document.write( "\n" ); document.write( "/20
\n" ); document.write( "n^2+4n -437=0\r
\n" ); document.write( "\n" ); document.write( "(n-19)(n+23) =0\r
\n" ); document.write( "\n" ); document.write( "Taking positive root
\n" ); document.write( "n=19\r
\n" ); document.write( "\n" ); document.write( "19 years\r
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