Let $S = \{1, 2, 3, 4, 5, 6\}$
1. How many subsets are there of cardinality 4?
(Note: you can enter “C(n,k)” for $\binom{n}{k}\text{.}$)
2. How many subsets of cardinality 4 have $\{2,3,5\}$ as a subset?
3. How many subsets of cardinality 4 contain at least one odd number?
4. How many subsets of cardinality 4 contain exactly one even number?