Permutations without repetition

The calculator computes the number of permutations of n elements. Number of permutations is the number of ways to choose a sample of n elements from a set of n distinct objects where order does matter and repetition are not allowed. There are n! (n factorial) ways of arranging n objects into an ordered sequence.

Calculation:

V_{k} (n) = \frac{n !}{( n - k ) !} n = 10 k = 4 V_{4} (10) = \frac{1 0 !}{( 1 0 - 4 ) !} = \frac{1 0 !}{6 !} = 10 \cdot 9 \cdot 8 \cdot 7 = 5040

The number of variations: 5040

A bit of theory - the foundation of combinatorics

Permutations

A permutation is an ordered arrangement of all n elements of a set, where each element is used exactly once, the order matters, and no repetition is allowed.

P (n) = n (n - 1) (n - 2) . . . 1 = n!

Example: We have 4 books. In how many ways can we arrange them side by side on a shelf?

Foundation of combinatorics in word problems

Peak
Uphill leads 2 paths and one lift. a) How many options back and forth are there? b) How many options to get there and back by the not same path are there? c) How many options back and forth are there that we go at least once a lift?
Hockey players
After we cycle, five hockey players sit down. What is the probability that the two best scorers of this crew will sit next to each other?
Dices throws
What is the probability that the two throws of the dice: a) Six falls even once b) Six will fall at least once
Choosing Colors for Sweater
Danka knits a sweater and has a choice of seven colors. a) How many ways can he choose three colors for the sleeves? b) He wants ribbons of four colors on his back. How many options does he have to choose from?
Different Report Cards
There are 19 children in class 6A, 7 subjects, and no one has a worse grade than a three. Can each of them have a different certificate? How many would have to be in the class so that everyone could not have another report card?