Suppose That the Market for Cigarettes Is Initially in Equilibrium $P = 60 - Q ^ { d }$

Multiple Choice

Suppose that the market for cigarettes is initially in equilibrium and is perfectly competitive. The demand curve can be expressed as $P = 60 - Q ^ { d }$ ; the supply curve can be expressed as $P = 0.5 Q ^ { s }$ . Quantity is expressed in millions of boxes per month. What are the amount traded and the price for this market?

A) Q = 40; P = 20
B) Q = 20; P = 40
C) Q = 30; P = 30
D) Q = 30; P = 15