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Dinda Erliananda Teaching Materials – SMA Class XII – Enumeration Rules

Proof (2):

Suppose there are n elements to be taken r elements to be placed in r places.
place to- Number of Ways

1 n

2 n– 1
3 n– 2

4 n– 3

r –2
r– 1

r

The many ways to fill all of those spaces are:

So,

Permutations for also called variations or .

Example 5:
Calculate using the formula above.

Answer:

4. Permutations with Some of the Same Elements

Suppose there are 7 flags, consisting of 4 colored flags other than white and 3
white flags. The flags will be installed on one side of the gate of an office. Even though

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