Permutations without repetition
The calculator calculates 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:
Vk(n)=(n−k)!n! n=10 k=4 V4(10)=(10−4)!10!=6!10!=10⋅9⋅8⋅7=5040
The number of variations: 5040
A bit of theory - the foundation of combinatorics
Permutations
The permutation is a synonymous name for a variation of the nth class of n-elements. It is thus any n-element ordered group formed of n-elements. The elements are not repeated and depend on the order of the elements in the group.P(n)=n(n−1)(n−2)...1=n!
A typical example is: We have 4 books, and in how many ways can we arrange them side by side on a shelf?
Foundation of combinatorics in word problems
- Fourland 3542
In Fourland, they only have four letters F, O, U, and R, and every word has exactly four letters. No letter may be repeated in any word. Write all the words that can be written with them. - Numbers 72404
How many numbers are less than 200, the digit sum of which is 6? - Positions 26151
How many positions are there to store three books on the shelf? - Four-member team
There are 14 girls and 11 boys in the class. How many ways can a four-member team be chosen so that there are exactly two boys in it?
- Probability 66424
There are 5 chocolate, 3 cottage cheese, and 2 apricot croissants in the bag. Croissants are randomly selected in bags. What is the probability of drawing 1 chocolate, 1 cheese, and 1 apricot croissant without returning? - Digit sum
How many are three-digit numbers that have a digit sum of 6? - A pizza
A pizza place offers 14 different toppings. How many different three-topping pizzas can you order? - Fruits
We want to plant five fruit trees in the garden, of which three are apple trees and two pears. How many different ways can we organize them? - Twins with friend
The twins Danka and Janka went to the cinema with their friend Betka. Only six seats in the second row were available in the cinema. The twins want to sit next to each other. Danka is always to the right of Janka, and Betka is near one of them. How many m
- Password dalibor
Kamila wants to change the password daliborZ by a) two consonants exchanged between themselves, b) changes one little vowel to such same great vowel c) makes these two changes. How many opportunities do you have a choice? - Toys
3 children pulled 9 different toys from a box. How many ways can toys be divided, so each child has at least one toy? - Locker combination
Todd forgot the first two numbers of his locker combination. The numbers can be any number 1 through 6. What is the probability that he will guess the first number correctly and the second number incorrectly? - Flags
How many different flags can be made from green, white, blue, red, orange, yellow, and purple materials, so each flag consists of three different colors? - Word
What is the probability that a random word composed of chars S, G, R, S, E, I, N, A, L, P, C, T, M, H, E, E will be the SPHERICALSEGMENT?
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