How to interpret income elasticity of demand
Hints: 


Looking at the definitions, if the income elasticity of demand for apples is 2, how much does apple demand increase when consumers' income increase by 10%?
Looking at the definitions, if the cross elasticity of demand between apple quantity and the orange price is 0.5, how much does apple demand decrease when the orange price falls by 15%?
How might you combine the increase with the decrease?


Multiplication might be a useful tool.