9th grade (14y) + multiplication principle - examples

  1. Practice
    telocvik How many ways can you place 20 pupils in a row when starting on practice?
  2. No. of divisors
    triangle_div How many different divisors has number ??
  3. 7 heroes
    7statocnych 9 heroes galloping on 9 horses behind. How many ways can sort them behind?
  4. Flags
    vlajka_cz How many different flags can be made from colors white, red, green, purple, orange, yellow, blue so that each flag consisted of three different colors?
  5. Vans
    shuttlevan In how many ways can 9 shuttle vans line up at the airport?
  6. Seating
    kupe_1 How many ways can 7 people sit on 3 numbered chairs (eg seat reservation on the train)?
  7. Guests
    hostia How many ways can 5 guests sit down on 6 seats standing in a row?
  8. 2nd class variations
    cards From how many elements you can create 6972 variations of the second class?
  9. Shelf
    bookshelf.JPG How many ways are there to arrange 6 books on a shelf?
  10. Phone numbers
    old_phone How many 9-digit telephone numbers can be compiled from the digits 0,1,2,..,8,9 that no digit is repeated?
  11. Rectangles
    rectangles How many rectangles with area 3032 cm2 whose sides is natural numbers are?
  12. Football league
    football In the 5th football league is 10 teams. How many ways can be filled first, second and third place?
  13. Playing cards
    playing_cards How many possible ways are to shuffle 7 playing cards?
  14. Pairs
    pair At the table sit 8 people, 4 on one side and 4 on the other side. Among them are 3 pairs. Every pair wants to sit opposite each other. How many ways can they sit?
  15. Morse alphabet
    morse_code Calculate how many words of Morse code to create compiling commas and dots in the words of one to four characters.
  16. Coin and die
    die Flip a coin and then roll a six-sided die. How many possible combinations are there?
  17. Lock
    combination-lock Combination lock will open when the right choice of 5 numbers (from 1 to 12 inclusive) is selected. A. How many different lock combinations are possible? B. Is he combination lock named appropriately?
  18. Subsets
    1venna_sets How many are all subsets of set ??
  19. Pizza
    pizza_1 A school survey found that 12 out of 15 students like pizza. If 6 students are chosen at random, what is the probability that all 6 students like pizza?
  20. Bits, bytes
    bits Calculate how many different numbers can be encoded in 16-bit binary word?

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