Using the combination formula, it is found that there are 495 ways to choose a 4-topping sandwich.
The order in which the toppings are chosen is not important, hence the combination formula is used to solve this question.
[tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by:
[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]
4 toppings are chosen from a set of 12, hence the number of ways is given by:
[tex]C_{12,4} = \frac{12!}{4!8!} = 495[/tex]
More can be learned about the combination formula at https://brainly.com/question/25821700
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