1. The problem asks to evaluate the combination $15C2$, which represents the number of ways to choose 2 items from 15 without regard to order.
2. The formula for combinations is:
$$nCr = \frac{n!}{r!(n-r)!}$$
where $n$ is the total number of items, and $r$ is the number of items chosen.
3. Substitute $n=15$ and $r=2$:
$$15C2 = \frac{15!}{2!(15-2)!} = \frac{15!}{2!13!}$$
4. Simplify the factorial expression by canceling $13!$:
$$15C2 = \frac{15 \times 14 \times \cancel{13!}}{2! \times \cancel{13!}} = \frac{15 \times 14}{2!}$$
5. Calculate $2! = 2 \times 1 = 2$:
$$15C2 = \frac{15 \times 14}{2}$$
6. Perform the multiplication and division:
$$15 \times 14 = 210$$
$$\frac{210}{2} = 105$$
7. Since the result is an integer, the value of $15C2$ is 105.
Final answer:
$$15C2 = 105$$
Combination 15C2 Ed61B2
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