Consider the market for a product with two types of potential users: group a and group b. Let's assume now that the following represent the demand for every individual in group a and b, respectively. There are 10 individuals of type a and 5 individuals of type Pₐ=5-0,5**Qₐ, Pᵦ=10-Q. Let this monopolist face a constant MC of MC=2. what is the optimal (profit-maximizing) two- part tariff that induces both types of consumers to buy?