Answer
$$\frac{12!}{4!\left(12-4\right)!}=495$$
Work Step by Step
We know the equation for combinations:
$$nC_r = \frac{n!}{r!\left(n-r\right)!}$$
Thus, we find:
$$\frac{12!}{4!\left(12-4\right)!}=495$$
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.