logo

CuriousTab

CuriousTab

Discussion


Home Aptitude Permutation and Combination Comments

  • Question
  • Find the number of ways, in which 12 different beads can be arranged to form a necklace .


  • Options
  • A. 11 !/2
  • B. 10 !/2
  • C. 12 !/2
  • D. Couldn't be determined

  • Correct Answer
  • 11 !/2 

    Explanation

    Number of arrangements of beads = (12 - 1) !, but it is not mentioned that either it is clockwise or anti - clockwise .
    So, required number of arrangements = [(12 - 1)! ] / 2 = 11 !/2


  • Permutation and Combination problems


    Search Results


    • 1. 
      In how many ways, can the letters of the word 'ASSASSINATION' be arranged, so that all the S are together?

    • Options
    • A. 10!
    • B. 14! (4!)
    • C. 151200
    • D. 3628800
    • Discuss
    • 2. 
      A child has four pockets and three marbles. In how many ways, the child can put the marbles in the pockets?

    • Options
    • A. 12
    • B. 64
    • C. 256
    • D. 60
    • Discuss
    • 3. 
      Boxes numbered 1, 2, 3, 4 and 5 are kept in a row and they are to be filled with either a red or a blue ball such that no two adjacent boxes can be filled with blue balls Then, how different arrangements are possible, given that all balls of a given colour are exactly identical in all respects?

    • Options
    • A. 8
    • B. 10
    • C. 15
    • D. 22
    • Discuss
    • 4. 
      In how many different ways can four books A, B, C and D be arranged one above another in a vertical order such that the books A and B are never in continuous position?

    • Options
    • A. 9
    • B. 12
    • C. 14
    • D. 18
    • Discuss
    • 5. 
      A man has 9 friends, 4 boys and 5 girls. In how many ways can he invite them, if there have to be exactly 3 girls in the invitees?

    • Options
    • A. 320
    • B. 160
    • C. 80
    • D. 200
    • Discuss
    • 6. 
      20 persons were invited to a party. In how many ways, they and the host can be seated at a circular table?

    • Options
    • A. 18 !
    • B. 19 !
    • C. 20 !
    • D. Couldn't be determined
    • Discuss
    • 7. 
      In how many different ways, 5 boys and 5 girls can sit on a circular table, so that the boys and girls are alternate?

    • Options
    • A. 2880
    • B. 2800
    • C. 2680
    • D. 2280
    • Discuss
    • 8. 
      How many necklaces of 12 beads can be made from 18 beads of various colours?

    • Options
    • A. [118 x 13!] / 2
    • B. [110 x 14! ] / 2
    • C. [119 x 13!] / 2
    • D. [110 x 12!] / 2
    • Discuss
    • 9. 
      In how many ways, a committee of 3 men and 2 women can be formed out of a total of 4 men and 4 women?

    • Options
    • A. 15
    • B. 16
    • C. 20
    • D. 24
    • Discuss
    • 10. 
      In how many ways, a cricket team of 11 players can be made from 15 players, if a particulars player is always chosen?

    • Options
    • A. 1835
    • B. 1001
    • C. 1635
    • D. 1365
    • Discuss


    Comments

    There are no comments.

Enter a new Comment