The Demand and Supply of Capital Are Given by Q^D

Multiple Choice

The demand and supply of capital are given by Q^D = 50 - 8r and Q^S = 4r - 10, where Q is the quantity of capital in millions of dollars and r is the interest rate measured as a percentage. What is the equilibrium quantity of capital?

A) $5 million
B) $60 million
C) $10 million
D) $12 million