Question 86
Given is an arbitrary floor plan composed of $n$ unit squares. Albert and Berta want to cover this floor with tiles, where each tile has the shape of a $1 \times 2$ domino or a T-tetromino. Albert has tiles of only one colour available, whereas Berta has dominoes in two colours and tetrominoes in four colours available. Albert can cover this floor plan with tiles in $a$ ways, Berta in $b$ ways. Under the assumption that $a \neq 0$, determine the ratio $b / a$.