Sets + reason - practice problems
Number of problems found: 52
- The vaccination
The vaccination coverage of the population is 80%. Unvaccinated make up 60% of all infected. What percentage are unvaccinated more likely to be infected? Consider N = 10,000 inhabitants and K = 1,000 infected. b. How many times more likely are unvaccinate
- Smoker male
For a person selected randomly from a certain population, events A and B are defined as follows. A = event the person is male B = event the person is a smoker. For this particular population, it is found that P(A ) = 0.53, P(B) = 0.15, and P(A n B ) = 0.1
- Three subjects
In a class of 40 students, 18 passed mathematics, 19 passed accounts, 16 passed economics, 5 mathematics and accounts only, 6 mathematics only, 9 accounts only, 2 accounts and economics only, if each student offered at least one of the subjects. a) how ma
- Gym center
80% of all visitors to the gym center enjoy a discount. 3/4 of all visitors go to practice regularly. All visitors who go to the gym regularly benefit from a discount. What percentage of all visitors do not go to the gym regularly but still use the discou
- Group of children
There is a group of children. There is a boy named Adam in each of the three children subgroup and a girl named Beata in each quartet (four-member subgroup). How many children can be in such a group and what are their names in that case?
- Venn diagram
University students chose a foreign language for the 1st year. Of the 120 enrolled students, 75 chose English, 65 German, and 40 both English and German. Using the Venn diagram, determine: - how many of the enrolled students chose English only - how many
- Language courses
Of the company's 60 employees, 28 attend an English course, 17 take a German course, and 20 do not attend any of these courses. How many employees attend both courses?
- Double probability
The probability of success of the planned action is 60%. What is the probability that we will achieve success at least once if this action is repeated twice?
- Alarm systems
What is the probability that at least one alarm system will signal the theft of a motor vehicle when the efficiency of the first system is 90% and of the independent second system 80%?
- Fall sum or same
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.
- Christmas or Easter
Please calculate this example by the Venn equation. They asked 73 students whether they like Christmas or Easter. 34 of them like one of the holidays. 39 loves Easter. There are twice as many students who wish both holidays as those who only love Easter.
- Brothers and sisters
There are 35 children in the class, 23 of them have a brother, and 27 of them have a sister. How many children have both a brother and a sister when there are 5 children in the class who have no brother or sister?
There are 36 pupils in the class. Nine girls wear glasses. Boys with glasses are five less than girls without glasses. Boys without glasses are two times more than girls without glasses. How many boys and how many girls?
- School trip
On a school trip, 17 of the 28 children bought ice cream or chocolate in a candy store. Twelve children bought chocolate, and nine children bought ice cream. How many children bought ice cream and chocolate? How many children did not buy ice cream? How ma
- Three excursions
Each pupil of the 9A class attended at least one of the three excursions. There could always be 15 pupils on each excursion. Seven participants of the first excursion also participated in the second, 8 participants of the first excursion, and 5 participan
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?
- 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?
- Ten boys
Ten boys chose to go to the supermarket. Six boys bought gum and nine boys bought a lollipop. How many boys bought gum and a lollipop?
- The Hotel
The Holiday Hotel has the same number of rooms on each floor. Rooms are numbered with natural numerals sequentially from the first floor, no number is omitted, and each room has a different number. Three tourists arrived at the hotel. The first one was in
- Marriage sttus
In our city, there are 3/5 of the women married to 2/3 of the men. Find what part of the population is free.
Sets - practice problems. Reason - practice problems.