Let the Market Demand for Rye Bread Be Given by Q

Let the market demand for rye bread be given by Q = 500 + I - 250P_rye + 400P_wheat,where Q is monthly demand in number of loaves,I is average monthly income in dollars,P_rye is the price of a loaf of rye bread,and P_wheat is the price of a loaf of wheat bread.If I = $1,000,P_rye = $2,and P_wheat = $3,calculate the following (based on 10% changes in denominators):
a)the arc price elasticity of demand for rye bread
b)the arc price elasticity of demand for wheat bread
c)the arc cross-price elasticity of demand for rye bread
d)the arc income elasticity of demand for rye bread