CAPE Pure Mathematics Unit 2 · May/June 2015 · Paper 1 · Question Q23

The binomial coefficient \binom{n}{2} is equivalent to

1. (A)\binom{n}{1} + \binom{n}{1}
2. (B)\binom{n}{n - 2}
3. (C)\binom{n - 2}{n}
4. (D)\binom{n}{n + 2}