Number of Permutations/Examples

Examples of Number of Permutations

$4$ from $52$

The number of ways of choosing $4$ objects in order from a set of $52$ (for example, cards from a deck) is:

${}^{52} P_4 = 52 \times 51 \times 50 \times 49 = \dfrac {52!} {48!} = 6 \, 497 \, 400$

Numbers Greater than $200$ from $\set {1, 2, 3, 4}$

Let $N$ be the number of ways you can make a number greater than $200$ using the digits $1$, $2$, $3$ and $4$ no more than once each.

Then:

$N = 42$

Even Integers from $\set {1, 2, 3, 4}$

Let $N$ be the number of even integers which can be made using all the digits $1$, $2$, $3$ and $4$.

Then:

$N = 12$