MathDB
Sideburns

Source: 2017 AMC 12B #13 / AMC 10B #18

February 16, 2017
AMCAMC 12reflection2017 AMC 12BcountingAMC 102017 AMC 10B

Problem Statement

In the figure below, 33 of the 66 disks are to be painted blue, 22 are to be painted red, and 11 is to be painted green. Two paintings that can be obtained from one another by a rotation or a reflection of the entire figure are considered the same. How many different paintings are possible?
[asy] size(100); pair A, B, C, D, E, F; A = (0,0); B = (1,0); C = (2,0); D = rotate(60, A)*B; E = B + D; F = rotate(60, A)*C; draw(Circle(A, 0.5)); draw(Circle(B, 0.5)); draw(Circle(C, 0.5)); draw(Circle(D, 0.5)); draw(Circle(E, 0.5)); draw(Circle(F, 0.5)); [/asy]
<spanclass=latexbold>(A)</span>6<spanclass=latexbold>(B)</span>8<spanclass=latexbold>(C)</span>9<spanclass=latexbold>(D)</span>12<spanclass=latexbold>(E)</span>15<span class='latex-bold'>(A) </span> 6 \qquad <span class='latex-bold'>(B) </span> 8 \qquad <span class='latex-bold'>(C) </span> 9 \qquad <span class='latex-bold'>(D) </span> 12 \qquad <span class='latex-bold'>(E) </span> 15