2000 AMC 10 Problems/Problem 12

Revision as of 17:47, 7 January 2009 by BOGTRO (talk | contribs) (New page: We have a recursion: <math>A_n=A_{n-1}+4(n-1)</math>. I.E. we add increasing multiples of <math>4</math> each time we go up a figure. So, to go from Figure 0 to 100, we add <math>4 \cd...)
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We have a recursion:

$A_n=A_{n-1}+4(n-1)$.

I.E. we add increasing multiples of $4$ each time we go up a figure.

So, to go from Figure 0 to 100, we add

$4 \cdot 1+4 \cdot 2+...+4 \cdot 99=4 \cdot 4950=19800$.


$19801$

B.

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