Possible choices using the multiplicacion principle:

Choose a t-shirt, a button down shirt, or a sweather, jeans or khakis, and either a red coat or a blue coat.

To find the total number of possible choices using the multiplication principle, we need to multiply the number of choices for each category together.

1. For the choice of a t-shirt, button-down shirt, or sweater, we have 3 options.

2. For the choice of jeans or khakis, we have 2 options.

3. For the choice of a red coat or a blue coat, we also have 2 options.

To find the total number of possible choices, we multiply the number of options for each category together:

3 (shirt choices) x 2 (pants choices) x 2 (coat choices) = 12.

Therefore, there are 12 possible choices using the multiplication principle.