In a free and competitive market?

1) there will be no surplus

2) there will be no shortage

3) demand and supply determine market outcome

4) all of the above

Assume, the cross-price elasticity E_x,y is positive, then

if the price of X goes down, demand for Y will go down

if the price of Y goes up, demand for X will go up

if E_x,y >1, then 1% decrease in price of one good will lead to more than 1% decrease in demand of the other good

All the above