Combinatorics - examples

  1. Cancel fractions
    zlomky_15 Compress the expression of factorial: (n+6)!/(n+4)!-n!/(n-2)!
  2. Normal distribution GPA
    normal_d_3 The average GPA is 2.78 with a standard deviation of 4.5. What are students in the bottom the 20% having what GPA?
  3. No. of divisors
    triangle_div How many different divisors has number ??
  4. Rectangle
    diagonal In rectangle with sides 3 and 10 mark the diagonal. What is the probability that a randomly selected point within the rectangle is closer to the diagonal than to any side of the rectangle?
  5. 7 heroes
    7statocnych 5 heroes galloping on 5 horses behind. How many ways can sort them behind?
  6. Ace
    ace From complete sets of playing cards (32 cards) we pulled out one card. What is the probability of pulling the ace?
  7. 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?
  8. Vans
    shuttlevan In how many ways can 5 shuttle vans line up at the airport?
  9. Seating
    kupe_1 How many ways can 7 people sit on 2 numbered chairs (eg seat reservation on the train)?
  10. Pediatrician
    doctor Pediatrician this month of 21 working days takes 3 days holidays. What is the probability that on Monday will be at work?
  11. Bureau of Labor
    UPSVAR Bureau of Labor is a state institution that provides mike and the rest for their so-called clients. The mission of the Bureau of Labor is spend taxpayer money to provide relaxation and benefits to those who do not want to work. Popularly speaking sense the
  12. Guests
    hostia How many ways can 8 guests sit down on 10 seats standing in a row?
  13. 2nd class variations
    cards From how many elements you can create 6972 variations of the second class?
  14. Word
    words What is the probability that a random word composed of chars H, T, M, A will be MATH?
  15. Shelf
    bookshelf.JPG How many ways are there to arrange 6 books on a shelf?
  16. Chocolates
    Chocolate In the market have 4 kinds of chocolates. How many ways can we buy 23 chocolates?
  17. 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?
  18. Two doctors
    dr_cvach Doctor A will determine the correct diagnosis with a probability 92% and doctor B with a probability 88%. Calculate probability of correct diagnosis if patient is diagnosed by both doctors.
  19. Rectangles
    rectangles How many rectangles with area 3002 cm2 whose sides is natural numbers are?
  20. Football league
    football In the 5th football league is 10 teams. How many ways can be filled first, second and third place?

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