1. **State the problem:** We want to find the number of ways to select 6 questions out of 10.
2. **Formula used:** The number of ways to choose $k$ items from $n$ items without regard to order is given by the combination formula:
$$\binom{n}{k} = \frac{n!}{k!(n-k)!}$$
3. **Apply the formula:** Here, $n=10$ and $k=6$, so:
$$\binom{10}{6} = \frac{10!}{6!(10-6)!} = \frac{10!}{6!4!}$$
4. **Simplify factorials:**
$$10! = 10 \times 9 \times 8 \times 7 \times 6!$$
So,
$$\binom{10}{6} = \frac{10 \times 9 \times 8 \times 7 \times \cancel{6!}}{6! \times 4!} = \frac{10 \times 9 \times 8 \times 7}{4!}$$
5. **Calculate $4!$:**
$$4! = 4 \times 3 \times 2 \times 1 = 24$$
6. **Evaluate numerator:**
$$10 \times 9 = 90$$
$$90 \times 8 = 720$$
$$720 \times 7 = 5040$$
7. **Divide numerator by denominator:**
$$\frac{5040}{24} = 210$$
**Final answer:** There are $210$ ways to select 6 questions out of 10.
Combinations Selection Ab33Fc
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