MathDB
Problem: 2004 AMC 10 #16

Source:

February 1, 2007
inductionUSAMTS

Problem Statement

The 5×5 5\times 5 grid shown contains a collection of squares with sizes from 1×1 1\times 1 to 5×5 5\times 5. How many of these squares contain the black center square? [asy]unitsize(6mm); defaultpen(linewidth(.8pt));
for(int i=0; i<=5; ++i) { draw((0,i)--(5,i)); draw((i,0)--(i,5)); } fill((2,2)--(2,3)--(3,3)--(3,2)--cycle);[/asy]<spanclass=latexbold>(A)</span> 12<spanclass=latexbold>(B)</span> 15<spanclass=latexbold>(C)</span> 17<spanclass=latexbold>(D)</span> 19<spanclass=latexbold>(E)</span> 20 <span class='latex-bold'>(A)</span>\ 12\qquad <span class='latex-bold'>(B)</span>\ 15\qquad <span class='latex-bold'>(C)</span>\ 17\qquad <span class='latex-bold'>(D)</span>\ 19\qquad <span class='latex-bold'>(E)</span>\ 20