The top of a table is rectangular and its dimensions are 6'×10'. Two rectangular portions of the table top are painted in blue colour; both these portions have dimensions 2·5'×8' and each of them has exactly two sides common with two edges of the table top. If the table is fixed to the ground and the remaining portion of the table top is painted in white, how many different patterns are possible when observed from above?

The 2.5'×8' rectangle must fit inside 6'×10' table with two sides coinciding with two edges of the table. The 8' side fits along the 10' edges (not 6' edges since 8 > 6), and the 2.5' side fits along the 6' edges. Each blue rectangle must share two adjacent edges of the table, meaning it sits in a corner with its 8'-side along a 10'-edge and its 2.5'-side along a 6'-edge. There are 4 corners. We need to place two such rectangles. The two rectangles must not overlap; depending on which corners chosen, certain combinations are valid. Considering symmetry and the fixed table (which removes rotational equivalence since position matters when fixed to ground), the number of distinct patterns is 4.