2020 AMC 8 Problems/Problem 12: Difference between revisions
Iirishabii (talk | contribs) Created page with "Solution 1 Notice that <math>5!</math> = <math>2*3*4*5,</math> and we can combine the numbers to make a bigger factorial. To change <math>9!</math> to <math>10!,</math> we ne..." |
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<cmath>10!=N!.</cmath> | <cmath>10!=N!.</cmath> | ||
Thus, <math>N=10(A).</math> | Thus, <math>N=10(A).</math> | ||
-iiRishabii | |||
Revision as of 23:53, 17 November 2020
Solution 1
Notice that 
= 
and we can combine the numbers to make a bigger factorial. To change 
to 
we need to multiply by 
which equals 
Therefore, we have
![\[10!*12=12*N!.\]](http://latex.artofproblemsolving.com/b/5/7/b57d51cc68f940f63a1dde3a63bbc125429d2bfc.png)
After canceling the 
we have
![\[10!=N!.\]](http://latex.artofproblemsolving.com/d/d/8/dd8b5a203f6c403ffb8a87279e697ee510eefb36.png)
Thus, 
-iiRishabii
