Question 12
A beaver has nine fir trees of three types, three trees of each type. Trees of the same type have the same height; different types have different heights.
It plants them in a \(3\times 3\) garden so every row and column contains each type once. A sign at each end of every row and column gives the number of trees visible from there. A taller front tree hides shorter trees behind it. The example illustrates the rule.
For the garden below, some signs are already given. What is the sum of all twelve signs after every sign is filled in?
It plants them in a \(3\times 3\) garden so every row and column contains each type once. A sign at each end of every row and column gives the number of trees visible from there. A taller front tree hides shorter trees behind it. The example illustrates the rule.
For the garden below, some signs are already given. What is the sum of all twelve signs after every sign is filled in?