Question 21
(SASMO 2017) As in Example 1 on the left, each number is the number of shaded cells that surround its cell. Shade the grid on the right according to the same rule. How many cells are shaded in that grid? Here surrounding cells share an edge with the numbered hexagon; numbered cells themselves remain unshaded. Do not include the cells of Example 1 in your answer.
Enter the numerical answer only.
Enter the numerical answer only.