The intersection problem for image Original Research Article

For every image image there exists a pairwise balanced design (PBD) of order image with exactly one block of size 5 and the rest of size 3. We will refer to such a PBD as a image. A flower in a image is the set of all blocks containing a given point. If image is a image and F is a flower, we will write image to indicate that F contains the block of size 5. The intersection problem for images is the determination of all pairs image such that there exists a pair of images image and image of order v containing the same block b of size 5 such that image. The flower intersection problem for images is the determination of all pairs image such that there exists a pair of images image and image of order v having a common flower image such that image. In this paper we give a complete solution of both problems.