document.write( "Question 1023304: Prove that 0,3 < S < 0,4
\n" ); document.write( "S= 1/(1*4) + 1/(4*7) + 1/(7*10) + ... + 1/(2014*2017)
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Algebra.Com's Answer #638817 by robertb(5830)\"\" \"About 
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S = \"%281%2F3%29%281-1%2F4%29%2B%281%2F3%29%281%2F4-1%2F7%29%2B%281%2F3%29%281%2F7-1%2F10%29\"+...+ \"%281%2F3%29%281%2F2011-1%2F2014%29+%2B+%281%2F3%29%281%2F2014-1%2F2017%29\"\r
\n" ); document.write( "\n" ); document.write( "=\"%281%2F3%29\"*(\"1+-+1%2F4+%2B+1%2F4+-+1%2F7+%2B+1%2F7+-+1%2F10\"+...+ \"1%2F2011-1%2F2014+%2B+1%2F2014-1%2F2017\")\r
\n" ); document.write( "\n" ); document.write( "=\"%281%2F3%29%281-1%2F2017%29\" = S\r
\n" ); document.write( "\n" ); document.write( "But \"S=+%281%2F3%29%282016%2F2017%29+=+672%2F2017+\"= 0.333168... >0.3, and also \r
\n" ); document.write( "\n" ); document.write( "\"S+=+%281%2F3%29%282016%2F2017%29+%3C+1%2F3+=+0.33333\"....< 0.4\r
\n" ); document.write( "\n" ); document.write( "Hence,\r
\n" ); document.write( "\n" ); document.write( "0.3 < S < 0.4.
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