# Combinatorics - examples - page 10

1. Combinations
If the number of elements increase by 3, it increases the number of combinations of the second class of these elements 5 times. How many are the elements?
2. Word MATEMATIKA
How many words can be created from the word MATEMATIKA by changing the order of the letters, regardless of whether or not the words are meaningful?
3. Points in plane
The plane is given 12 points, 5 of which is located on a straight line. How many different lines could by draw from this points?
4. Elements
If the number of elements is decreased by two the number of permutations is decreased 30 times. How many elements are?
5. Seagull
Artificially created island in the shape of a circle with a radius of 50 m is overgrown with grass. The only exception is a landing area for helicopters in the shape of a rectangle measuring 15 m and 8 m. What is the probability that the flying seagull (wi
6. Variation equation
Solve combinatorics equation: V(2, x+8)=72
7. Combinations
How many elements can form six times more combinations fourth class than combination of the second class?
8. 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
9. Dice
We throw five times the dice. What is the probability that six fits exactly twice?
10. 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
11. Dice
We throw 10 times a play dice, what is the probability that the six will fall exactly 4 times?
12. 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?
13. Page numbering
The book has 88 pages. How many times is the number 4 used for the book numbering?
14. 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.
15. 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.
16. 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?
17. 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?
18. 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
19. Seven
Seven friends agree to send everyone a holiday card. How many postcards were sent?
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

Do you have an interesting mathematical example that you can't solve it? Enter it, and we can try to solve it.

To this e-mail address, we will reply solution; solved examples are also published here. Please enter e-mail correctly and check whether you don't have a full mailbox.

Would you like to compute count of combinations?