We observe the demand function for food is given by the equation
Qdpf =80−3Ppf+0.1I+0.5Ppd
Qdpf is the number of food, Ppf is the price of food, I is the income , Ppd is the price of drink)
We know that:Ppf= 30, I=110, and Ppd= 20.
The income elasticity of demand for food will be:
能写一下解题思路？
