Reason + multiplication principle - math problems

  1. Fall sum or same
    dices2 Find the probability that if you roll two dice, it will fall the sum of 10, or the same number will fall on both dice.
  2. Birth
    probability Let's assume that the probability of the birth of a boy and a girl in the family is the same. What is the probability that in a family with five children, the youngest and oldest child is a boy?
  3. Divide
    hrusky How many different ways can three people divide 7 pears and 5 apples?
  4. Twenty-five
    prime How many three-digit natural numbers are divisible by 25?
  5. Boys and girls
    dancers There are 20 boys and 10 girls in the class. How many different dance pairs can we make of them?
  6. 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?
  7. Graduation party
    dancers There are 15 boys and 12 girls at the graduation party. Determine how many four couples can be selected.
  8. One three
    dice We throw two dice. What is the probability that max one three falls?
  9. Holidays with grandmam
    saty We have packed three T-shirts - white, red, orange and five pants - blue, green, black, pink and yellow. How many days can we spend with the old mother if we put on a different combination of clothes every day?
  10. Bookshelf and books
    bookshelf How many can we place 7 books in a bookshelf?
  11. A jackpot
    jackpot3 How many times must I play this jackpot to win? A jackpot of seven games having (1 X 2), i. E. , home win or away win.
  12. Boys and girls
    dices2_10 There are 11 boys and 18 girls in the classroom. Three pupils will answer. What is the probability that two boys will be among them?
  13. Each with each
    tenis_3 Five pupils from 3A class played table tennis. How many matches did they play with each other?
  14. Inverted nine
    clock-night-schr In the hotel,, Inverted nine" each hotel room number is divisible by 6. How many rooms we can count with three-digit number registered by digits 1,8,7,4,9?
  15. Peaches
    broskve There are 20 peaches in the pocket. 3 peaches are rotten. What is the probability that one of the randomly picked two peaches will be just one rotten?
  16. Dinning room
    cukriky_14 How many different combinations can we choose if there are 3 soups, 5 kinds of main dish and 2 desserts in the dining room?
  17. Sweater
    colours_3 Dana confuses sweater and wool has a choice of seven colors. In how many ways she can choose from three colors to the sleeves?
  18. Lunch
    skola_15 Seven classmates go every day for lunch. If they always come to the front in a different order, will be enough school year to take of all the possibilities?
  19. Glass with icecream
    zmrzlina_7 We have 6 kinds of ice cream and 5 kinds of fruit. We put 3 cups of ice cream and 2 fruits into each glass. How many can unique decorated glasses be?
  20. Bridge cards
    cards2 How many bridge hands are possible containing 4 spades,6 diamonds, 1 club, and 2 hearts?

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