Question 8. A 3x3x3 cube is made from white, gray, and black 1x1x1 cubes, as shown in the first diagram. The other two diagrams show the white part and the black part of the cube. Which of the following diagrams shows the gray part? If we take a look at our 3x3x3 cube and look at the gray faces, we can mark them out here, here, and here. Now we can compare these to what we see in the potential answers. In answer A, this matches here and here. However, this gray cube is incorrectly placed, so this will not be one of our solutions. Similarly, if we look at diagram D, we see that the same cubes apply here. However, if we look at one cube in front, we notice that this is not the way that this looks in the 3x3x3 cube. So D will also not be a correct solution. We can cross this out. Next, we can consider this side face, which makes a zigzag pattern. If we look at diagram B, we see that it is with an additional cube, so this will not be the correct answer. We can cross B off. Finally, we look at C, and notice that it is missing one cube from the zigzag pattern, so this is also incorrect. We are left with our answer, which will be E.

3x3x3 cube

diagram comparison

gray cubes

option elimination

correct structure