关于economic一道题~

关于economic一道题~
Income elasticity of demand
All foods 0.10
Beef 0.26
Margarine -0.22
Fresh potatoes -0.43
Fruit juices 0.95
Bread -0.18
Price elasticity of demand
Beef -1.24
Bread -0.25
Fresh potatoes -0.14
Fruit juices -0.65
Margarine -0.37
You are the owner of a grocery store.How would you increase the total revenue of the following products based on information of the price elasticities given in the table above?
a.beef
b.fresh potatoes