### Instruction: Suppose I have 6 shirts and 5 ties.  How many shirt-and-tie outfits can I make?### Response: I need to choose one shirt and one tie for each outfit, and the choices are independent of each other.
That means I can use the multiplication principle: the number of outfits is the product of the number of shirts and the number of ties.
So the answer is 6 times 5, which is 30.