Combinatorial number - practice problems
Number of problems found: 146
- Tv dinner tray
I'm trying to calculate total possible unique potential combinations, but I'm trying to solve for a tv dinner tray with 4 little sections for one each of: meat, veggie, starch, dessert. What makes this more complex is we have different types of meats/vegg
- Pass a test
The student has to pass a test that contains 10 questions. For each of them, he chooses one of 5 answers, with just one being correct. The student did not prepare for the test, so he chooses the answers at random. What are the probabilities that the stude
- Balls in row
Calculate the number of ways of placing 4 black balls, 4 turquoise balls and 5 gold balls in a row.
- Population variance
In a California community college, 60% of students will transfer to a college in the CSU system. The number of students in a sample who will transfer follows a binomial distribution. If 8 students are randomly selected, find the population variance σ² of
- The flag
The flag should consist of 3 different colored stripes. Available colors: white, red, blue, green and yellow. Specify: A) number of all flags B) number of flags with a blue stripe C) number of flags with a blue stripe in the middle D) the number of flags
- The three
The three boys Adam, Boris and Cyril are to be taken on a two-seater ski lift. How many different removal options are there? What would it be like if four boys or five were to be taken away?
- Binomial probability
What is the binominal probability that at least 4 of the 6 trials (n=6) are succeeded where φ = 0.50?
- Draw a triangle
We have line segments with lengths of 3cm, 5cm, 6cm, 7cm and 9cm. What is the probability in % that if I randomly select three of them I will be able to draw a triangle?
C(6,3) + 3 P(6,3)
- Committee 2
How many committee consisting of 3 women and 2 men can be formed from a group of 6 woman and 5 men?
- There 8
There are 7 women and 5 men in a department. a) how many ways can a committee of 3 people be selected? b) how many ways can a committee of 2 men and 1 woman be selected? c) how many ways can a committee of at least 2 woman be selected (3 people total)?
- Created trio
What is the probability that in the created trio, which consists of 19 boys and 12 girls, they will be: a) the boys themselves b) the girls themselves c) 2 boys and 1 girl?
- Bernoulli distribution
The production of solar cells produces 2% of defective cells. Assume the cells are independent and that a lot contains 800 cells. Approximate the probability that less than 20 cells are defective. (Answer to the nearest 3 decimals).
- The six
The six boys are to be led up the hill by a two-seater lift. How many options are there?
Data showed that 22% of people in a small town was infected with the COVID-19 virus. A random sample of six residents from this town was selected. Find the probability that exactly two of these residents was infected.
The drug successfully treats 90% of cases. Calculate the probability that he will cure at least 18 patients out of 20?
The germination of seeds of a certain species of carrot is 96%. What is the probability that at least 25 seeds out of 30 will germinate?
- Wimbledon finals
Serena Williams made a successful first serve 67% 0f the time in a Wimbledon finals match against her sister Venus. If she continues to serve at the same rate the next time they play and serves 6 times in the first game, determine the probability that: 1.
The father wants to plant 2 seedbeds of carrot and 2 seedbeds of onion. Use a tree chart to find how many different options for placing the seedbeds he has.
- Honored students
Of the 25 students in the class, 10 are honored. How many ways can we choose 5 students from them, if there are to be exactly two honors between them?
See also our combinations calculator.