The demand for kitty litter, in pounds, is , Q(D)=100-P(D)-P(C)+2m, where P(D) is the price of kitty litter, P(C) is the price of cat food, and is income.
1. What is the price elasticity of demand for kitty litter when P(D)=30,P(C)=20, m=50?
2. What is the income elasticity of demand for kitty litter when P(D)=30,P(C)=20, m=50?
3. What is the cross-price elasticity of demand for kitty litter when P(D)=30,P(C)=20, m=50? Are kitty litter and cat food substitutes or complements?