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
- 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? - Gertrude 62304
Six boys and six girls (among them Emil, Félix, Gertrude, and Hanka) want to dance. The number of ways they can make six (mixed) couples if Emil does not want to dance with Gertrude and Hanka wants to dance with Felix is? - Characters 63404
How many characters can we create from two commas and four dots? - Book Store
The Mabini Book Store (MBS) is reducing the prices of Mathematics books for promotion. The store has 6 Algebra books, 6 Geometry books, and 5 Statistics books to be arranged on a shelf. Books of the same kind are to be placed beside each other. How many w - Parking 72644
How many ways can ten cars park side by side in a parking lot? - Six segmants
Given are 6 line segments with lengths of 3 cm, 4 cm, 5 cm, 7 cm, 8 cm, and 9 cm. How many equilateral triangles can make from them? List all the options. - Different 4533
Five different positive numbers are written on the board. Determine the largest possible number of pairs formed from them in which the sum of the two elements equals one of the five numbers written on the board. - Elements
If the number of elements is decreased by two, the number of permutations is decreased 30 times. How many elements are? - Digits How many natural numbers greater than 4000 are formed from the numbers 0,1,3,7,9 with the figures not repeated, B) How many natural numbers will be less than 4000, and can the numbers be repeated?
- Three-digit 6690
How many three-digit numbers do we make from the numbers 4,5,6,7? - Spouses 61294
Ten married couples board the train, which has five cars. How many ways can they take if no two spouses want to be in the exact vehicle? - Calculated 67234
There are 13 boys and 17 girls in the class. The weeklies are always either two girls or a boy and a girl. The teacher calculated that she has 357 ways to create a pair of weekly newspapers. However, Anetka did not come to school on Monday morning. How ma - Competition in the class There are 10 students in the class, of which 8 are girls and two are boys. We want to select three for the competition. What is the probability that they will be: a) 2 girls and 1 boy b) 1 girl and 2 boys c) 3 girls d) 3 boys e) at least 2 girls
- Seven segments display
Electronic devices sometimes use the type of digits below, where each digit uses some short stripes. For example, seven uses three small stripes. What is the largest three-digit number that you can make if you use twenty stripes?
more math problems »
