how to calculate this question? TQ

(b) The market demand and market supply functions for coffee in Alice's cafe is as follows: Qd = 55 - 5P Qs = -50 + 10P (i) Identify the market equilibrium price and equilibrium quantity. (2 marks) (ii) Assuming that Alice's cafe is giving a RM1 off promotion for their 1 year anniversary, what do you expect to happen in the market? Support your answers with figures. (4 marks) (iii) Identify the new market equilibrium price and equilibrium quantity if the new demand function is Qd = 70 -5P. (2 marks) [Total : 20 marks]