The arrangement blue tiles = 4, red tiles = 2 and black tiles = 3.

To find the permutations of 9 tiles of which 4 of blue tiles, 2 of red tiles and 3 black tiles.

The number of permutations of n objects of which p are alike,  q are alike and r are alike is .

                (Cancel common terms)

                      (Multiply: )

                         (Divide: )

The permutation is 1260.