- Intro to Combinations and Permutations
- Permutations with Repetition
- Permutations without Repetition
- Permutations Formula
- Android Lock Screen
- Tigers and Bears - Oh My
Combination without Repetition
- Combination Formula
- Combining Combinations
The String of Beads
- Combinations with Repetition I
- Combinations with Repetition II
Combinations with Repetition I
In the previous questions you solved Permutations by converting them to Combinations. You can also solve difficult combinations by turning them into easier ones. We will start with an easy example, and in the next node cover the general case.
You want to create many Strings of Beads, so you go to the store to buy 100 beads. They only have 2 colors (black and white), and you can decide how many beads you want to take of each color. You don't care about the order and you don't even have to take both colors.