In: Economics
Option E is correct - cherries and apples are complements
Cross price elasticity of demand is the responsiveness of change in quantity demanded of one good because of the change in price of the other. It is given by the following formula:
Cross price elasticity of demand for good X = * (Py/Qx)
Here Qx is the quantity demaned of good X and Py is the price of good Y.
The two goods are said to be substitutues if their cross price elasticity of demand is positive.
The two goods are said to be complementary of their cross price elascticity of demand is negative.
We are given the following equation:
Qc = m-20Pc-40Pa, where, m is the income, Pc is the price of a pound of cherreis, Pa is the price of a pound of apples and Qc is the quantity of cherreis.
Differentiating the eqaution with respect to Pa, we get,
= -40
Cross price ealsticity of demand = -40* (Pa/Qc)
Since the value of cross price elasticity of demand is negative, the goods are complements.