Applied circular 4! = 24 ways In the Group [red, blue, White] can be organized by blue, the middle two. Therefore, The number of ways to manage, according to proposition 24 x 2 = 48 = method.
The circular was brought to 4! = 24 means the [red, blue, white] can be arranged by the blue in the middle of the second series in a number of ways so that we want to = 2 x 24 = 48 ways.