Variations + multiplication - examples

  1. No. of divisors
    triangle_div How many different divisors has number ??
  2. 7 heroes
    7statocnych 5 heroes galloping on 5 horses behind. How many ways can sort them behind?
  3. 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?
  4. Vans
    shuttlevan In how many ways can 5 shuttle vans line up at the airport?
  5. Seating
    kupe_1 How many ways can 7 people sit on 2 numbered chairs (eg seat reservation on the train)?
  6. Guests
    hostia How many ways can 8 guests sit down on 10 seats standing in a row?
  7. Football league
    football In the 5th football league is 10 teams. How many ways can be filled first, second and third place?
  8. 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?
  9. 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.
  10. Coin and die
    die Flip a coin and then roll a six-sided die. How many possible combinations are there?
  11. Lock
    combination-lock Combination lock will open when the right choice of 3 numbers (from 1 to 25 inclusive) is selected. A. How many different lock combinations are possible? B. Is he combination lock named appropriately?
  12. Bits, bytes
    bits Calculate how many different numbers can be encoded in 16-bit binary word?
  13. Three digits number
    plot How many are three-digit integers such that in they no digit repeats?
  14. Cars plates
    car_plate How many different licence plates can country have, given that they use 3 letters followed by 3 digits?
  15. Friends in cinema
    cinema_1 5 friends went to the cinema. How many possible ways can sit in a row, if one of them wants to sit in the middle and the remaining's place does not matter?
  16. Peak
    lanovka.JPG Uphill leads 2 paths and 1 lift. a) How many options back and forth are there? b) How many options to get there and back by not same path are there? c) How many options back and forth are there that we go at least once a lift?
  17. Seating rules
    school_class In a class are 24 seats but in 7.B class are only 18 students. How many ways can student seat? (The class has 12 benches. A bench is for a pair of students.) Result (large number) logarithm and thus write down as powers of 10.
  18. 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?
  19. Three-digit
    numbers_5 How many three-digit natural numbers is greater than 321 if no digit in number repeated?
  20. A three-digit numbers
    clocks_1 Determine the total number of positive three-digit numbers that contain a digit 6.

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