Pronunciation of Permutation/Combination Notation and Ordered Pairs Quick question: How am I supposed to pronounce (or read in my head) the following?  
$P(n,k)$ or $C(n,k)$
Also, how am I supposed to pronounce (or read in my head) this?  
$K \times M = \{(x,y): x\in K$ and $y\in M\}$

$P(n,k)$ is pronounced the number of $k$ such permutations of $n$ and $C(n,k)$ is pronounced $n$ choose $k$.
