Question 2
Mason built a pyramid using identical cubes. It is shown below from different angles. Mason paints the whole pyramid green. How many cubes have exactly 3 faces painted green?
Interpretation of the dark source diagrams: use four centered, solid square layers of side lengths 7, 5, 3 and 1 cubes from bottom to top. Paint every exposed face, including the underside. The clear plan-view schematic is editorial and makes this intended model explicit; it does not recover hidden grid lines from the scan.
Interpretation of the dark source diagrams: use four centered, solid square layers of side lengths 7, 5, 3 and 1 cubes from bottom to top. Paint every exposed face, including the underside. The clear plan-view schematic is editorial and makes this intended model explicit; it does not recover hidden grid lines from the scan.