Combinatorial number + multiplication principle - examples

  1. Boys and girls
    dices2_10 There are 11 boys and 18 girls in the classroom. Three pupils will answer. What is the probability that two boys will be among them?
  2. Each with each
    tenis_3 Five pupils from 3A class played table tennis. How many matches did they play with each other?
  3. Word
    words What is the probability that a random word composed of chars T, H, A, M will be MATH?
  4. Rectangles
    rectangles How many rectangles with area 3032 cm2 whose sides is natural numbers are?
  5. Candy
    bulls How many ways can divide 16 identical candies to 4 children?
  6. Stacks
    euro_stacks Annie has a total of $ 702. The money must be divided into stacks so that each buyer has the same amounth of dollars. How many options she have?
  7. Pairs
    dvojice From the five girls and four boys teachers have to choose one pair of boy and girl. A) How many such pairs of (M + F)? B) How many pairs where only boys (M + M)? C) How many are all possible pairs?
  8. 2nd class combinations
    color_circle From how many elements you can create 4560 combinations of the second class?
  9. Commitee
    committees A class consists of 6 males and 7 females. How many committees of 7 are possible if the committee must consist of 2 males and 5 females?
  10. Math logic
    children_7 There are 20 children in the group, each two children have a different name. Alena and John are among them. How many ways can we choose 8 children to be among the selected A) was John B) was John and Alena C) at least one was Alena, John D) maximum one w
  11. Cinema
    stale_kvoka How many ways can be divided 11 free tickets to the premiere of "Jáchyme throw it in the machine" between 6 pensioners?
  12. The camp
    diary At the end of the camp a 8 friends exchanged addresses. Any friend gave remaining 7 friends his card. How many addresses they exchanged?
  13. Three-digit numbers
    poker_hand_ranking How many three-digit numbers are from the numbers 0 2 4 6 8 (with/without repetition)?
  14. Combinatorics
    fontains The city has 7 fountains. Works only 6. How many options are there that can squirt ?
  15. Hockey
    hokej Hockey match ended 8:2. How many different matches could be?
  16. Weekly service
    school_table.JPG In the class are 20 pupils. How many opportunities have the teacher if he wants choose two pupils randomly who will weeklies?
  17. travel agency
    nevesta Small travel agency offers 5 different tours at honeymoon. What is the probability that the bride and groom choose the same tour (they choose independently)?
  18. Count of triangles
    SquareTriangle Given a square ABCD and on each side 8 internal points. Determine the number of triangles with vertices at these points.
  19. Hockey game
    Hockey In the hockey game was made 6 goals. Czech played against Finland. Czechs won 4:2. In what order to fall goals? How many game sequence was possible during the game?
  20. Salami
    salama How many ways can we choose 5 pcs of salami, if we have 6 types of salami for 10 pieces and one type for 4 pieces?

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