2016 AMC 10A Problems/Problem 1: Difference between revisions
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==Solution== | ==Solution== | ||
<cmath>\frac{11!-10!}{9!} = \frac{9!(10 \cdot 11 -10)}{9!} = 10 \cdot 11 - 10 =\boxed{\textbf{(B)} 100}</cmath> | <cmath>\frac{11!-10!}{9!} = \frac{9!(10 \cdot 11 -10)}{9!} = 10 \cdot 11 - 10 =\boxed{\textbf{(B)}\;100.}</cmath> | ||
Revision as of 17:59, 3 February 2016
Problem
What is the value of 
?
Solution
![\[\frac{11!-10!}{9!} = \frac{9!(10 \cdot 11 -10)}{9!} = 10 \cdot 11 - 10 =\boxed{\textbf{(B)}\;100.}\]](http://latex.artofproblemsolving.com/1/a/4/1a461813226c67877e8d0b9fc7186a4622efeb10.png)
