Finding the Number of Permutations for n Different Objects

the number of permutations of "n" different objects is n!

The Permutation Formula

Determining the Value of nPr

Common Guidelines for nPr

• if r = 0, nPr = 1
• if r = 1, nPr = n
• if r = n - 1 or if r = n, nPr = n!
  

Evaluating Permutations Using a Graphing Calculator

Solving for n in nPr

Solving for r in nPr

Arranging Books

How many ways can you arrange 13 books, grouped in 3 trilogies of 3 books, 4 books, and 6 books, if each trilogy must stay together?

Permutations With Duplicate Objects

• the number of permutations with "n" total objects and "r1" duplicate objects of one kind, "r2" duplicate objects of another kind, etc, is n!/(r1!*r2!*r3!)

Calculating Permutations with Duplicate Objects

Calculating Permutations of Duplicate Numbers

Getting From Point A to B

How many paths are there from point A to B?

Arranging Coin Flips

How many ways can flipping a coin 10 times result in 3 heads and 7 tails, in any order?