# Sets - problems

1. Pupils
There are 27 pupils in the classroom. They can swim 21 and ski nine pupils. Neither swim nor ski three pupils. How many pupils can swim and ski?
2. Probability of intersection
Three students have a probability of 0.7,0.5 and 0.4 to graduated from university respectively. What is the probability that at least one of them will be graduated?
3. Chamber
In the chamber light is broken and all from it must be taken at random. Socks have four different colors. If you want to be sure of pulling at least two white socks, we have to bring them out 28 from the chamber. In order to have such certainty for the pai
4. Lentilka
Lentilka made 31 pancakes. 8 don't fill with anything, 14 pancakes filled with strawberry jam, 16 filled with cream cheese. a) How many Lentilka did strawberry-cream cheese pancakes? Maksik ate 4 of strawberry-cream cheese and all pure strawberry pancake
5. Freedom
In the city are 3/9 of women married for 3/6 men. What proportion of the townspeople is free (not married)? Express as a decimal number.
6. Two doctors
Doctor A will determine the correct diagnosis with a probability 86% and doctor B with a probability 86%. Calculate probability of correct diagnosis if patient is diagnosed by both doctors.
7. Camp
In a class are 26 children. During the holidays 16 children were in the camps and 14 children on holiday with their parents. Determine the minimum and maximum number of children that may have been in the camp and on holiday with their parents at the same
8. Pizza master
Master says that he can splits pizza to 16 parts by five equals straight cuts. Is it possible?
9. Subsets
How many are all subsets of set ??
10. Pairs
From the five girls and four boys teachers have to choose one pair of boy and girl. A) How many such pairs of (M + F)? B) How many pairs where only boys (M + M)? C) How many are all possible pairs?
11. Count of roots
How many solutions has equation x. y = 7757 with two unknowns on the set of natural numbers?
12. Segments
Line segments 62 cm and 2.2 dm long we divide into equal parts which lengths in centimeters is expressed integer. How many ways can we divide?
13. Classroom 3
How many children are in the classroom, where 13 children are higher than Lenka and 9 children lower than Lenka?
14. Math logic
There are 20 children in the group, each two children have a different name. Alena and John are among them. How many ways can we choose 8 children to be among the selected A) was John B) was John and Alena C) at least one was Alena, John D) maximum one w
15. Glasses
Imagine a set of students in your class (number of students: 19), who wears glasses. How much minimum and maximum element may contain this set.
16. Trousers
In the class was 12 students. Nine students wearing trousers and turtleneck eight. How many students worn trousers with a turtleneck?