Past data indicate that the current market share for three companies (say C1, C2, and C3) are respectively 0.25, 0.45, and 0.30. In a district of 20 potential customers (assuming that products will be sold according to the respective market shares),

a) compute the probability that company 1 will sell 10 products, company 2 will sell 5, and company 3 will sell 5 products.

b) given that that company 3 has already sold 5 products, what are the chances that company 1 will sell 10 products?

c) compute the correlations between the market shares of each company.