A consumer consumes good X

A consumer consumes good X. Explain the effects of fall in prices of related goods on the demand of X.

The effect of fall in price of related goods on demand of X is stated below:
Fall in the price of related goods:(i) Price of substitute good decreases.
(ii) Price of complementary good decreases.
Change in demand of X:(i)Demand of good X also decreases.
(ii)Demand of good X increases.