Let \(A = \{1,2,3,\ldots,9\}\text{.}\)
How many subsets of \(A\) are there? That is, find \(|\pow(A)|\text{.}\) Explain.
How many subsets of \(A\) contain exactly 5 elements? Explain.
How many subsets of \(A\) contain only even numbers? Explain.
How many subsets of \(A\) contain an even number of elements? Explain.