Reason + variations - math problems

  1. Two groups
    skola The group of 10 girls should be divided into two groups with at least 4 girls in each group. How many ways can this be done?
  2. Seating
    kupe_1 How many ways can 5 people sit on 4 numbered chairs (e. G. , seat reservation on the train)?
  3. 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?
  4. Three digits number
    plot How many are three-digit integers such that in they no digit repeats?
  5. Seven-segmet
    7segment Lenka is amused that he punched a calculator (seven-segment display) numbers and used only digits 2 to 9. Some numbers have the property that their image in the axial or central symmetry was again give some number. Determine the maximum number of three-d
  6. 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?
  7. 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?
  8. Variations 3rd class
    cubic From how many elements we can create 13,800 variations 3rd class without repeating?
  9. 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
  10. Three-digit numbers
    poker_hand_ranking How many three-digit numbers are from the numbers 0 2 4 6 8 (with/without repetition)?
  11. 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
  12. Three digits number
    3digit From the numbers 1, 2, 3, 4, 5 create three-digit numbers that digits not repeat and number is divisible by 2. How many numbers are there?
  13. Chess
    chess How many different ways can initiate a game of chess (first pass)?
  14. 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
  15. 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?
  16. Pupils
    wolfenstein_3d Four pupils is going via dark hall. Start at one side and have to get to the other side for 17 minutes. They have only one lamp for the trip. The corridor is narrow, they can therefore go up two pupils at a time and go at the slower speed. Each pupil went.
  17. Sum on dice
    dices2 We have two dice. What is the greater likelihood of fall a total sum 7 or 8 ? (write 7, 8 or 0 if the probabilities are the same)?
  18. Four swords
    fight Obelix has three helmets, four swords and five shields. How many swords must make at the blacksmith forge Metallurgix to be able to walk another 90 days in unique armor?
  19. Lines
    lines_4 How many lines can be draw with 8 points, if three points lie on one line and the other any three points do not lie on the same line?
  20. Alarm clock
    clock-night-schr The old watchmaker has a unique digital alarm in its collection that rings whenever the sum of digits of the alarm is equal to 21. Find out when the alarm clock will ring. What is their number? List all options . ..

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