Let [math]A = \{1,2,3,\ldots,9\}\text{.}

- How many subsets of [math]
A are there? That is, find [math]|\pow(A)|\text{.} Explain. - How many subsets of [math]
A contain exactly 5 elements? Explain. - How many subsets of [math]
A contain only even numbers? Explain. - How many subsets of [math]
A contain an even number of elements? Explain.