Combinatorics - practice for 12 year olds - page 4 of 6
Number of problems found: 107
- Three-digit numbers
We have digits 0, 1, 4, and 7 that we cannot repeat. How many three-digit numbers can we write from them? You can help by listing all the numbers. - Dining 5004
The dining room offers three types of soups and four types of main courses. How many ways can we choose soup and the main course? - Down syndrome
Down syndrome is one of the serious diseases caused by a gene mutation. Down syndrome occurs in approximately every 550-born child. Express the incidence of Down's syndrome in newborns at per mille. - To improve
To improve her handwriting, Paula practices writing the numbers 1 to 200 in words. How often will she have written the word "one" in all?
- Double-digit 17103
How many double-digit numbers can we create from the digits 1, 2, 3, 4, 5, and 6 if we can repeat the digits in the number? - Calculation 73364
From the number 5,4,0,7,8, create three-digit numbers, so they do not repeat and solve the problem by calculation. - Three-digit 5226
How many different three-digit natural numbers can be created so that the digits are different and the last digit is 0? - Four-digit numbers
How many four-digit numbers can we make from the numbers 2, 6, 3, 5, 1, and 9 if we cannot repeat the numbers in the number? - People 7331
How many people must be in a group for at least two of them to be born in the same month?
- Determine 79624
There are 5 roads from city A to city B, 3 from city B to city C, and 4 from city C to city D. Determine the number of paths that go from A to D via B and C. - Probability 8408
From the group of 18 players I am, the coach selects nine players. What is the probability that I will be among the players chosen? - Three-digit 5093
How many can you create three-digit numbers from the numbers 1,3,5,7 if we must not repeat the numbers? - Natural numbers
How many natural numbers can we create less than 301 from the number 0,1,2,3,6,7? - Probability 80825
What is the probability that two fives are rolled when two dice are rolled if we know that the sum of both numbers is divisible by five?
- Girlfriends 4107
Four girlfriends want to take a photo together. How many different ways can they stand side by side? - Representative 8328
How many ways can a commander and a representative of a 20-member group be elected? - Boy-girl 6766
How many boy-girl pairs can we create from a class of 15 boys and 16 girls? - Olympics
How many ways can six athletes be placed on the podium at the Olympics? Depend on the color of the metal. - Positions 26151
How many positions are there to store three books on the shelf?
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