Question 23
A square floor is completely covered with non-overlapping $1\times1$ white and black square tiles. The tiles along the two longest diagonals are black, while the remaining tiles are white. How many white tiles are there if the floor contains 41 black tiles?
The diagram is a smaller example of the coloring pattern, not the actual floor.

The diagram is a smaller example of the coloring pattern, not the actual floor.
