Combinatorics - math word problems

  1. Seating
    kupe_1 How many ways can 6 people sit on 6 numbered chairs (e. G. , seat reservation on the train)?
  2. Lottery
    loteria_1 The lottery is 60000 elk in which 6200 wins. What is the probability that the purchase of 12 elks won nothing?
  3. School trip
    hostel_1 The class has 19 students. What different ways students can be accommodated in the hostel, where available 3× 2-bed, 3× 3-bed and 1× 4-bed rooms. (Each room has its unique number)
  4. Dice
    dices How many times must throw the dice, the probability of throwing at least one six was greater than 90%?
  5. Party
    party-informatikov At the party everyone clink with everyone. Together, they clink 406 times. How many people were at the party?
  6. Phone numbers
    old_phone How many 7-digit telephone numbers can be compiled from the digits 0,1,2,..,8,9 that no digit is repeated?
  7. Family
    stork_bocian What is the probability that a family with 7 childrens have: exactly 5 girls? 7 girls and 0 boys? Consider the birth probability of a girl is 48.69% and boy 51.31%.

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