Assume the demand function for basketballs is given by QD=150-3P+0.1i where P=the price of basketballs and I=average income of consumers. Also, assume the supply of basketballs is given by QS=2P. If the market for basketballs is perfectly competitive, and the average income is equal to $1500, what are the equilibrium price and quantity? What if a 20% income is introduced?