Weekly service

In the class are 20 pupils. How many opportunities have the teacher selected two pupils who will have a week-class service randomly?

Correct result:

n =  190

Solution:

n=C2(20)=(202)=20!2!(202)!=201921=190



We would be pleased if you find an error in the word problem, spelling mistakes, or inaccuracies and send it to us. Thank you!






Showing 0 comments:
avatar




Tips to related online calculators
Would you like to compute count of combinations?

You need to know the following knowledge to solve this word math problem:

Next similar math problems:

  • Peaches
    broskve There are 20 peaches in the pocket. 3 peaches are rotten. What is the probability that one of the randomly picked two peaches will be just one rotten?
  • Class pairs
    pair_1 In a class of 34 students, including 14 boys and 20 girls. How many couples (heterosexual, boy-girl) we can create? By what formula?
  • Research in school
    numbers_1 For particular research in high school, four pupils are to be selected from a class with 30 pupils. Calculate the number of all possible results of the select and further calculate the number of all possible results, if it depends on the order in which th
  • Math logic
    children_7 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 wa
  • School parliament
    slovakia There are 18 boys and 14 girls in the class. In how many ways can 3 representatives be elected to the school parliament, if these are to be: a) the boys themselves b) one boy and two girls
  • Practice
    telocvik How many ways can you place 20 pupils in a row when starting on practice?
  • Raffle
    tombola_3 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?
  • Examination
    examination The class is 21 students. How many ways can choose two to examination?
  • Combinatorics
    fontains The city has 7 fountains. Works only 6. How many options are there that can squirt ?
  • Graduation party
    dancers There are 15 boys and 12 girls at the graduation party. Determine how many four couples can be selected.
  • Boys and girls
    dancers There are 20 boys and 10 girls in the class. How many different dance pairs can we make of them?
  • Classroom
    ziaci_7 Of the 26 pupils in the classroom, 12 boys and 14 girls, four representatives are picked to the odds of being: a) all the girls b) three girls and one boy c) there will be at least two boys
  • Dining questionnaire
    dotaznik In the class of 32 pupils, the class teacher delivered a satisfaction questionnaire to the school canteen. Eleven people have questioned whether they are satisfied with the dining room. The completed questionnaire also included the vote of the class teach
  • Competition
    sutaz 15 boys and 10 girls are in the class. On school competition of them is selected 6-member team composed of 4 boys and 2 girls. How many ways can we select students?
  • Honored students
    metals 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?
  • 2nd class combinations
    color_circle From how many elements you can create 4560 combinations of the second class?
  • Neighborhood
    glasses_1 I have 7 cups: 1 2 3 4 5 6 7. How many opportunities of standings cups are there if 1 and 2 are always neighborhood?