Answer:
a. The equilibrium price is $45, the quantity is 45 parking spaces for each parking lot, and the profit per parking lot owner is $1125.
b. The equilibrium price will increase to $60, the quantity will decrease to 20 parking spaces for parking lot A, and the profit per parking lot owner will decrease to $800.
c. The equilibrium price will increase to $50, the quantity will decrease to 20 parking spaces for parking lot A, and the profit per parking lot owner will decrease to $1000.