Suppose that when the price of good X falls from $10 to $8, the quantity demanded of good Y rises from 20 units to 25 units. Using the midpoint method, the cross-price elasticity of demand is
a. -1.0, and X and Y are complements.
b. -1.0, and X and Y are substitutes.
c. 1.0, and X and Y are complements.
d. 1.0, and X and Y are substitutes.
a
Economics