A close friend invited Czairyn to her birthday party. Czairyn has 4 new blouses (stripes, with ruffles, long-sleeved, and sleeveless) and 3 skirts (red, pink, and black) in her closet reserved for such occasions. Assuming that any skirt can be paired with any blouse, in how many ways can Czairyn select her outfit? List the possibilities. How many blouse-and-skirt pairs are possible? Construct a tree diagram to illustrate the list of possibilities.