# Desks

A class has 20 students. The classroom consists of 20 desks, with 4 desks in each of 5 different rows. Amy, Bob, Chloe, and David are all friends, and would like to sit in the same row. How many possible seating arrangements are there such that Amy, Bob, Chloe, and David are all in the same row?

**Result****Leave us a comment of example and its solution (i.e. if it is still somewhat unclear...):**

**Showing 0 comments:**

**Be the first to comment!**

#### To solve this example are needed these knowledge from mathematics:

## Next similar examples:

- Variations

Determine the number of items when the count of variations of fourth class without repeating is 42 times larger than the count of variations of third class without repetition. - Trainings

The table contains tennis training schedule for Saturday's younger students during the winter indoor season. Before the start of the summer season is preparing a new training schedule. Tomas Kucera will be able to practice only in the morning, sisters Kova - Chess

How many ways can select 4 fields on classic chess board with 64 fields, so that fields don't has the same color? - Task of the year

Determine the number of integers from 1 to 10^{6}with ending four digits 2006. - Toys

3 children pulled 12 different toys from a box. Many ways can be divided toys so that each children had at least one toy? - Numbers

How many different 7 digit natural numbers in which no digit is repeated, can be composed from digits 0,1,2,3,4,5,6? - Playing cards

How many possible ways are to shuffle 7 playing cards? - Medals

In how many ways can be divided gold, silver and bronze medal among 21 contestant? - Neighborhood

I have 7 cups: 1 2 3 4 5 6 7. How many opportunities of standings cups are there if 1 and 2 are always neighborhood? - Election 4

In a certain election there are 3 candidates for president 5 for secretory and 2 for tresurer. Find how many ways the election may (turn out/held). - PIN - codes

How many five-digit PIN - code can we create using the even numbers? - Metals

In the Hockey World Cup play eight teams, determine how many ways can they win gold, silver and bronze medals. - Tricolors

From the colors - red, blue, green, black and white, create all possible tricolors. - 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 this two changes. How many opportunities have a choice? - Tokens

In the non-transparent bags are red, white, yellow, blue tokens. We 3times pull one tokens and again returned it, write down all possibilities. - Olympics metals

In how many ways can be win six athletes medal positions in the Olympics? Metal color matters. - Elections

In elections candidate 10 political parties. Calculate how many possible ways can the elections finish, if any two parties will not get the same number of votes.