Elements

If the number of elements is decreased by two the number of permutations is decreased 30 times. How many elements are?

Correct answer:

n =  6

Step-by-step explanation:

P(n)=n! P(n)=30 P(n2) n!=30(n2)! n(n1)(n2)!=30(n2)! n(n1)=30  n(n1)=30 n2n30=0  a=1;b=1;c=30 D=b24ac=1241(30)=121 D>0  n1,2=b±D2a=1±1212 n1,2=1±112 n1,2=0.5±5.5 n1=6 n2=5   Factored form of the equation:  (n6)(n+5)=0  n=n1=6=6

Our quadratic equation calculator calculates it.




Did you find an error or inaccuracy? Feel free to write us. Thank you!



avatar







Tips to related online calculators
Looking for help with calculating roots of a quadratic equation?
See also our permutations calculator.
Do you have a linear equation or system of equations and looking for its solution? Or do you have a quadratic equation?
Would you like to compute count of combinations?

Related math problems and questions:

  • Combinations
    kvadrat If the number of elements increase by 3, it increases the number of combinations of the second class of these elements 5 times. How many are the elements?
  • Permutations with repetitions
    numbers2 How many times the input of 1.2.2.3.3.3.4 can be permutated into 4 digits, 3 digits and 2 digits without repetition? Ex: 4 digits = 1223, 2213, 3122, 2313, 4321. . etc 3 digits = 122.212.213.432. . etc 2 digits = 12, 21, 31, 23 I have tried permutation fo
  • VCP equation
    combinatorics3 Solve the following equation with variations, combinations and permutations: 4 V(2,x)-3 C(2,x+ 1) - x P(2) = 0
  • Permutations without repetition
    permutations From how many elements, we can create 720 permutations without repetition?
  • 2nd class combinations
    color_circle From how many elements you can create 4560 combinations of the second class?
  • Combinations of sweaters
    sveter I have 4 sweaters two are white, 1 red and 1 green. How many ways can this done?
  • Word
    words What is the probability that a random word composed of chars E, Y, G, E, R, O, M, T will be the GEOMETRY?
  • School trip
    hostel The class has 19 students. What different ways can students be accommodated in the hostel, where available 3× 2-bed, 3× 3-bed and 1× 4-bed rooms? (Each room has its unique number)
  • Possible combinations - word
    dices2 How many ways can the letters F, A, I, R be arranged?
  • There
    Permutations There were 12 members on the commission. In the vote, 5 members were in favor and 7 members were against the proposal. In how many ways could the commission vote?
  • Three workplaces
    workers How many ways can we divide nine workers into three workplaces if they need four workers in the first workplace, 3 in the second workplace, and 2 in the third?
  • Vans
    shuttlevan In how many ways can 9 shuttle vans line up at the airport?
  • Seating
    kupe How many ways can 6 people sit on 6 numbered chairs (e. g. , seat reservation on the train)?
  • Classroom
    ziaci 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
  • Playing cards
    playing_cards How many possible ways are to shuffle 7 playing cards?
  • The flag
    germanyflag 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
  • Boys and girls
    boy There are eight boys and nine girls in the class. There were six children on the trip from this class. What is the probability that left a) only boys b) just two boys