Please help with the following microeconomics question.

Background information: (there is nothing missing or cropped out)

Wagga is a little town in Australia where there is only one physio-therapy firm that provides a service (massage) to two distinct groups of customers. Group 1 consists of 100 identical pensioners (aged 65 or above) and group 2 consists of 100 identical non-pensioners. Within each groups, the customers have the same individual demand curve. The inverse demand function of a pensioner is P1 = A - BQ1 where Pi is the price charged by the firm (per minute of massage performed on a pensioner) and Q, is the quantity demanded (the numbers of minutes of massage the pensioner demands at that price). We assume that A > 0 and B > 0. The demand function of a non-pensioner is P = a -bQ2 where P, is the price charged by the firm (per minute of massage performed on a non-pensioner) and Q, is the quantity demanded (the numbers of minutes of massage the non-pensioner demands at that price). We assume that a > 0 and 630. Assume that the marginal cost is c, a non-negative constant, where c