In a market where the demand curve is Q_d = 100 - 2P and the supply curve is Q_s = 20 + 3P, what is the equilibrium quantity? (Please answer in millions per year)

• A. 60
• B. 80
• C. 52
• D. 40

Answer: (C)

Verified step by step guidance

1. Identify the equilibrium condition where quantity demanded equals quantity supplied: \(Q_d = Q_s\).
2. Set the demand function equal to the supply function: \$100 - 2P = 20 + 3P$.
3. Solve the equation for the price \(P\): rearrange terms to isolate \(P\) on one side.
4. Once you find the equilibrium price \(P^*\), substitute it back into either the demand or supply equation to find the equilibrium quantity \(Q^*\).
5. Express the equilibrium quantity in millions per year as requested.