Using the combination formula, the probability that Rosa's mom chooses sausage and onion is given by:
B. .
The order in which the toppings are chosen is not important, hence the <em>combination formula </em>is used to solve this question.
<h3>What is the combination formula?</h3>
is the number of different combinations of x objects from a set of n elements, given by:
2 toppings are chosen from a set of 8, hence the number of options is given by:
.
Sausage and onion correspond to one topping, hence the probability is given by:
B. .
More can be learned about the combination formula at brainly.com/question/25821700
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