1. The problem statement, all variables and given/known data In how many different non-overlapping ways can a (2 x 10) rectangle be covered by (1 x 1) and (1 x 3) rectangles. 2. Relevant equations 3. The attempt at a solution I've never done any question like this. The only solution I can think of is a brute force method but I doubt that's the way it is intended to be solved. Any hints? Thanks.