Combinatorics + reason - practice problems - page 2 of 19
Number of problems found: 378
- Together 70124
Twins Ela and Nela came to the cinema together with their friend Hela. Only the first 10 seats in the third row are free. How many ways can they be seated if the twins want to sit next to each other, with Nela always to Ela's left and Hel right next to on - Possibilities 5058
Adamko is two years old and does not want to clean his toys. One night, the toy fairy came to his room and saw legos, a police car, blocks, and a train lying on the floor. The fairy decided to take 3 toys from Adamko. How many choices does a trio of toys - Different 79704
Thirty-two boys and 34 girls came to the dance. How many different dance pairs can they make, given that each team is given: they can only dance for 1 minute and then take turns in 5 seconds? Calculate how long the dance evening would last for all the pai - Socks
Ben's favorite colors are blue and green. He has six blue socks and six green socks in his sock drawer. Unfortunately, they are completely mixed up, and one day, he has to grab some socks to wear in complete darkness. How many socks (minimum) does he have
- Seven-segmet
Lenka is amused that he punched a calculator (seven-segment display) number and used only digits 2 to 9. Some numbers have the property that She again gave their image in the axial or central symmetry some number. Determine the maximum number of three-dig - Different 9711
A new bus route network was built. There are three stops on each line. In addition, every two lines either do not have a common stop or have only one common stop. What is the largest number of tracks there can be in a town if we know there are only nine d - Left-handed 2571
Eva, Lucia, Barbora, Ivana, and Slávka are good friends, so they always want to sit at one long table next to each other in biology class. How many ways can they sit if Slavka is left-handed and, therefore, always wants to sit on the left side of the tabl - Sum or product
What is the probability that two dice fall will have the sum of seven or product 12? - Desks
A class has 20 students. The classroom consists of 20 desks, with four desks in each of 5 different rows. Amy, Bob, Chloe, and David are all friends and would like to sit in the same row. How many possible seating arrangements are there such that Amy, Bob
- Competition 67314
The coach must choose two students from Sam, Jura, Emma, Dan, and Nika to go to the competition. He knows them well and knows that Samo will only go with Jura or Ema, and Dano will not go with Ema. How many pairs does the trainer have to choose from? - Dulikovci 56311
Dulikovci, Elikovci, Filikovci, and Galikovci visited each other often last month. Each family visited each family exactly once. How many visits did all four families make together? If two families came to visit one family simultaneously, count it twice. - Twelve flowers
A florist has roses, tulips, daffodils, and carnations to use in flower arrangements. If she were to make an arrangement using 12 flowers, how many different combinations of these four types of flowers would be possible? - Possibilities 66804
Without listing all the possibilities, calculate how many different pairs can be made A) of 12 pupils who want to go down a water slide on a two-seater inflatable in the water park. B) of 15 pupils who want to ride toy cars in the amusement park. - Complexity 30631
Here, you have a task to think about but don't look for great complexity in it. You have 6 bulbs connected here. A to F and 6 switches No. 1 to No. 6. Your task will be to gradually determine which bulbs will always be on if any of the switches are in the
- Tournament 4771
Eight tennis players took part in the tennis tournament. They were divided into two groups of four. In each group, everyone played each other once. The winner of the first group played the winner of the second group in the final. They did not play other m - Differently 69514
Gabika wants to wear pants, a blouse, a skirt, and a T-shirt to the party. She has two pairs of pants, 3 blouses, 3 skirts, and 4 T-shirts to choose from. How many parties can she attend if everyone wants to go dressed differently? - Different 66944
It was Tibor's birthday, and he bought 8 different cookies for his friends (Horalky, Tatanky, Kávenky, Attack, Mila, Anita, Mäta, Lina). He put them all in a box, and each friend could choose two pieces. Tanya chose first. Which two cookies could Táňa cho - Karolína
Carolina chose five bodies from the kit - white, blue, and gray cubes, a blue cylinder, and a white triangular prism. How many different roof towers can be built one by one if all the blue bodies (cube and cylinder) are not placed on top? - Cinema
How many ways can 11 free tickets to the premiere of "Jáchyme throw it in the machine" be divided between 6 pensioners?
Do you have homework that you need help solving? Ask a question, and we will try to solve it.