A lamp business uses the following equations to express supply and demand as a function of price and quantity for its lamps:
Supply: Price = 30 - Quantity
Demand: Price = 10 + 3 × Quantity
How many lamps does the business need to sell in order for the supply of lamps to equal the demand for lamps exactly-i.e., for the supply and demand to be at equilibrium?
Correct Answer:
Your Answer:
Explanation
5 Since the supply and demand are at equilibrium, set the two expressions equal to one another and solve for the number of lamps:
30 - Quantity = 10 + 3 × Quantity
20 = 4 × Quantity
5 = Quantity