If you buy three pairs of jeans, four sweaters, and three pairs of boots, how many new outfits (consisting of a new pair of jeans, a new sweater, and a new pair of boots) will you have?

This is a fundamental counting principle problem. We have 3 things to choose from: jeans, sweaters, and boots. We make a blank for each type of item, fill in the blank with the number of possible choices for that item and then multiply the numbers that we have together.
3 * 4 * 2 = 24.