5.2 A water park in Melbourne, Australia, charges a uniform ticket price, A, for all visitors and a separate price, p, per trip down the water slide. Every day, 800 teenagers visit the park. Each of them has a demand function q1 = 15 - p. In addition, 200 adults visit the park every day. Each adult has a demand function q2 = 10 - p. The park’s objective is to set A and p so as to maximize its profit given that it has no (non-sunk) cost and must charge both groups the same prices. What are the optimal A and p?