Can you please help me with this exercise?

The marketing department of The Great Bombay Tea Company has estimated

the weekly demand for its brand of gourmet pizza as

Q = 500 100P + 50I + 20Py + 30A

where Q is the number of pizzas (000's), P is the market-determined price of

Bombay's pizza, I is weekly per capita income, Py is the price of the brand of

pizza sold by Universal Foods, Inc., and A is Bombay's weekly advertising

expenditures ($000's). The supply equation for Bombay's gourmet pizza is

Q = 1,800 + 450P

a. What is the relationship between Bombay's pizza and Universal's pizza?

b. Suppose that I = $200, Py = $20 and A = $100. What is the equilibrium

price and quantity of Bombay pizza?

c. Suppose that Bombay's chief economist predicts that the current economic

expansion will increase weekly per capita income to $255. What effect will

this have on the equilibrium price and quantity?

d. Based on your answer to part c, how would you characterize Bombay's

pizza?