document.write( "Question 508353: Let b be a positive integer. If you determined the sum of b factorial (b!) where b goes from 1 to 2000 what would be the last two digits (ones and tens digit) of the sum? \n" ); document.write( "

Algebra.Com's Answer #341074 by richard1234(7193) $\"\"$ $\"About$

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Since any factorial greater than 10! is divisible by 100, we can simply discard all of these numbers (since they won't influence the last two digits) and just find the last two digits of 1! + 2! + ... + 9!. The last two digits are 13. \n" ); document.write( "

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