What is the relation between goodX and good Y in each case of with fall in price X demand for good will rise give reason?

The relationship between good X and good Y can be characterized by their nature as substitutes or complements. If good X and good Y are substitutes, a fall in the price of good X will lead to an increase in the demand for good X, as consumers will prefer the cheaper option over good Y. Conversely, if they are complements, a decrease in the price of good X can also increase the demand for both goods, as lower prices may encourage consumers to buy more of both goods together.