# Combinatorics - math word problems

1. Combinations How many elements can form six times more combinations fourth class than combination of the second class?
2. Box and whisker plot Construct a box and whisker plot for the given data. 56, 32, 54, 32, 23, 67, 23, 45, 12, 32, 34, 24, 36, 47, 19, 43
3. Boys and girls There are eight boys and nine girls in the class. There were six children on the trip from this class. What is the probability that left a) only boys b) just two boys
4. Dice We throw five times the dice. What is the probability that six fits exactly twice?
5. Triangles Five sticks with a length of 2,3,4,5,6 cm. How many ways can you choose three sticks to form three sides of a triangle?
6. Dice We throw 10 times a play dice, what is the probability that the six will fall exactly 4 times?
7. Classroom Of the 26 pupils in the classroom, 12 boys and 14 girls, four representatives are picked to the odds of being: a) all the girls b) three girls and one boy c) there will be at least two boys
8. Families 2 There are 729 families having 6 children each. The probability of a girl is 1/3 and the probability of a boy is 2/3. Find the the number of families having 2 girls and 4 boys.
9. Page numbering The book has 88 pages. How many times is the number 4 used for the book numbering?
10. Test The teacher prepared a test with ten questions. The student has the option to choose one correct answer from the four (A, B, C, D). The student did not get a written exam at all. What is the probability that: a) He answers half correctly. b) He answers.
11. Raffle There are 200 draws in the raffle, but only 20 of them win. What is the probability of at least 4 winnings for a group of people who have bought 5 tickets together?
12. Left handed It is known that 25% of the population is left-handed. What is the probability that there is a maximum of three left-handers at a seminar where there are 30 participants?
13. Each with each Five pupils from 3A class played table tennis. How many matches did they play with each other?
14. Seven Seven friends agree to send everyone a holiday card. How many postcards were sent?
15. Boys and girls 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?
16. Three students Three students independently try to solve the problem. The first student will solve a similar problem with a probability of 0.6, the second student will solve at a probability of 0.55, and the third will solve at a probability 0.04. The problem is resolved
17. Dd 2-digit numbers Find all odd 2-digit natural numbers compiled from digits 1; 3; 4; 6; 8 if the digits are not repeated.
18. First man What is the likelihood of a random event where are five men and seven women first will leave the man?
19. Diagonals What x-gon has 54 diagonals?
20. Utopia Island A probability of disease A on the island of Utopia is 40%. A probability of occurrence among the men of this island, which make up 60% of all the population (the rest are women), is 50%. What is the probability of occurrence of A disease among women on Uto

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