The 120 consumers were asked about their buying preferences concerning a product that is sold in the market under three labels. the results were: 12 buy only those sold under label a, 25 buy only those sold under label b, 26 buy only those sold under label c, 15 buy only those sold under labels a and b, 10 buy only those sold under labels a and c, 12 buy only those sold under labels b and c and 8 buy the product sold under all three labels.