2000 PMWC Problems/Problem T4


Use the four colours red, yellow, blue and green to fill in the regions of the following diagram so that the adjacent regions are not the same colour. How many different ways are there to colour the regions?

[asy] import geometry; draw((0,0)--(3,0)--(3,2)--(0,2)--cycle); draw((0,1)--(1.5,2)); draw((2.3,0)--(2.3,0.7)--(3,0.7)); draw(ellipse((1.5,1),0.6,0.5)); //Credit to chezbgone2 for the diagram[/asy]


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