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?


n =  120


Solution in text n =

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

Showing 0 comments:
1st comment
Be the first to comment!

Would you like to compute count of combinations? See also our variations calculator. See also our permutations calculator.

Next similar examples:

  1. Trainings
    tenis 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
  2. Chess
    sachovnica How many ways can select 4 fields on classic chess board with 64 fields, so that fields don't has the same color?
  3. Flags
    vlajka_cz How many different flags can be made from colors red, blue, green, white, yellow so that each flag consisted of three different colors?
  4. Digits
    numbers2_18 How many natural numbers greater than 4000 which are formed from the numbers 0,1,3,7,9 with the figures not repeated, B) How many will the number of natural numbers less than 4000 and the numbers can be repeated?
  5. Three-digit numbers
    poker_hand_ranking How many three-digit numbers are from the numbers 0 2 4 6 8 (with/without repetition)?
  6. Toys
    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?
  7. Pairs
    pair At the table sit 10 people, 5 on one side and 5 on the other side. Among them are 3 pairs. Every pair wants to sit opposite each other. How many ways can they sit?
  8. Hockey players
    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?
  9. Lock
    combination-lock Combination lock will open when the right choice of 3 numbers (from 1 to 25 inclusive) is selected. A. How many different lock combinations are possible? B. Is he combination lock named appropriately?
  10. Numbers
    numbers_3 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?
  11. Eight blocks
    cuboids Dana had the task to save the eight blocks of these rules: 1. Between two red cubes must be a different color. 2. Between two blue must be two different colors. 3. Between two green must be three different colors. 4. Between two yellow blocks must be four
  12. Peak
    lanovka.JPG Uphill leads 2 paths and 1 lift. a) How many options back and forth are there? b) How many options to get there and back by not same path are there? c) How many options back and forth are there that we go at least once a lift?
  13. Vans
    shuttlevan In how many ways can 5 shuttle vans line up at the airport?
  14. Subsets
    1venna_sets How many are all subsets of set ??
  15. 7 heroes
    7statocnych 5 heroes galloping on 5 horses behind. How many ways can sort them behind?
  16. Olympics
    olimpiada-medaliile In how many ways can be placed 6 athletes on the podium at the Olympics? Depend on the color of the metal.
  17. Dices throws
    dices_4 What is the probability that the two throws of the dice: a) Six falls even once b) Six will fall at least once