The demand for coffee is given by the function: = 8.5 ― p ― 0.3p +0.1, where p is the price of coffee, ps is the price of sugar, and Y is consumer income.
a. Calculate the income elasticity of demand when = 5 and = 25 and interpret your answer.
b. Calculate the cross-price elasticity of demand when = 5 and P = 0.5 and interpret your answer.
please be elaborate