Answer:
First, we need to list all the possible selections and the number of options that each selection has:
Style of home: 5 options.
Style of garage: 6 options.
Style of decks: 5 options.
Style of carpeting: 6 options.
The number of different combinations of possible homes is equal to the product between the number of options for each selection.
This is:
C = 5*6*5*6 = 900
So there are 900 possible houses (that are all different in some aspect)