Guest Posted October 5, 2008 Report Share Posted October 5, 2008 What is the remainder when 2008! (that is 2008 factorial which is rly rly big) is divided by 7? Think about what a factorial is, write out what you are doing when finding the factorial of 2008 might help. For those who get it i know it's simple but it had me stumped for a while =) Quote Link to comment Share on other sites More sharing options...
0 Guest Posted October 5, 2008 Report Share Posted October 5, 2008 factorial as in 2008!/7? Quote Link to comment Share on other sites More sharing options...
0 Guest Posted October 5, 2008 Report Share Posted October 5, 2008 yes Quote Link to comment Share on other sites More sharing options...
0 unreality Posted October 5, 2008 Report Share Posted October 5, 2008 (edited) 2008! = 2008 * 2007 * ... * 8 * 7 * 6 * ... * 2 * 1 Dividing by any integer number from 1 to 2008 is possible to give a remainder of 0 Edited October 5, 2008 by unreality Quote Link to comment Share on other sites More sharing options...
0 Guest Posted October 5, 2008 Report Share Posted October 5, 2008 as 2008! is 2008*2007....*7....*1 meaning in contains *7 in just reverse that. i.e. x! has a remainder of 0 when divided by any number between 1 and x, so the answer to the original question is 0 Quote Link to comment Share on other sites More sharing options...
0 Guest Posted October 5, 2008 Report Share Posted October 5, 2008 yeah unreality is right, gj guess it wasn't as hard as i thought after all =P Quote Link to comment Share on other sites More sharing options...
0 Guest Posted October 5, 2008 Report Share Posted October 5, 2008 But what's the remainer of 48!/49? Quote Link to comment Share on other sites More sharing options...
0 Guest Posted October 5, 2008 Report Share Posted October 5, 2008 (edited) But what's the remainer of 48!/49? 12413915592536072670862289047373375038521486354677760000000000/49 has a remainder of 0 =) Edited October 5, 2008 by K4D Quote Link to comment Share on other sites More sharing options...
0 Guest Posted October 6, 2008 Report Share Posted October 6, 2008 (edited) But what's the remainer of 48!/49? zero because 48! = 48 x ... x 14 x ... x 7 x .... x 1 = n x 14 x 7 (for some n) = n x 2 x 7 x 7 = 2n x 49 Now... the remainder of 42!/43 is another question altogether... Edited October 6, 2008 by armcie Quote Link to comment Share on other sites More sharing options...
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What is the remainder when 2008! (that is 2008 factorial which is rly rly big) is divided by 7?
For those who get it i know it's simple but it had me stumped for a while =)
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