Home
Class 12
MATHS
If one quarter of all three element subs...

If one quarter of all three element subsets of the set `A={a_(1), a_(2), a_(3), ......., a_(n)}` is equal to the three element subsets which contains the element az, then n is

A

10

B

12

C

14

D

20

Text Solution

Verified by Experts

The correct Answer is:
B
Promotional Banner

Topper's Solved these Questions

  • PERMUTATIONS & COMBINATIONS

    AAKASH SERIES|Exercise EXERCISE-II|229 Videos

  • PARTIAL FRACTIONS

    AAKASH SERIES|Exercise PRACTICE EXERCISE|31 Videos

  • PROBABILITY

    AAKASH SERIES|Exercise Practise Exercise|165 Videos

Similar Questions

Explore conceptually related problems

The number of all three element subsets of set {a_(1),a_(2),a_(3),.......,a_(n)} which contain a_(3) is

If 20% of three element subsets of the set {a_(1),a_(2),a_(3),.......,a_(n)} are three element subsets with an element a_(1) , then n is

If one quarter of all three element subsets of the set A = { a_1 ,a_2,a_3,. . . ,a_n} contains the element a_3 then n=

The number of all three element subsets of the {a_1,a_2 ,a_3 ,… a_n} which contain a_3 is

If the number of subsets with 8 elements from the set A={a_(1),a_(2),a_(3),.........a_(n)},nge8 is five times the number of such subsets containg a_(4) , then

The number of subsets of the set A={a_(1),a_(2),………..a_(n)} which contain even number of elements is

a_(n) = n/(n+2) , a_(3) = ……….

The number of constant functions that can be defined from the set A={a_(1), a_(2), a_(3)…, a_(n)} to the set B={b_(1), b_(2),….b_(n)} is

a_(n) = 2^(n), a_(5) = ………

AAKASH SERIES-PERMUTATIONS & COMBINATIONS-PRACTICE EXERCISE
  1. The number of ways in which 1440 can be divided into two factors exclu...

    Text Solution

    |

  2. The sum of odd divisors of 360 is

    Text Solution

    |

  3. If one quarter of all three element subsets of the set A={a(1), a(2), ...

    Text Solution

    |

  4. The number of subsets of the set A={a(1),a(2),………..a(n)} which contain...

    Text Solution

    |

  5. The number of subsets of {1,2,3,. . . .9} conatining at least one ...

    Text Solution

    |

  6. A set contains (2n+1) elements. If the number of subsets of this set w...

    Text Solution

    |

  7. In an election, no. of candidates is one more than the number of perso...

    Text Solution

    |

  8. The number of ways of dividing 12 boys into 2 groups of 7,5 boys r...

    Text Solution

    |

  9. The number of ways in which 12 books can be put in 3 shelves, 4 on eac...

    Text Solution

    |

  10. The number of ways of dividing 100 scouts into 3 squads of 50, 30, 20 ...

    Text Solution

    |

  11. The number of ways of dividing 15 cards into 3 groups of 5 cards each ...

    Text Solution

    |

  12. If the number of subsets with 8 elements from the set A={a(1),a(2),a(3...

    Text Solution

    |

  13. At an election three wards of a town of a are canvassed by ...

    Text Solution

    |

  14. Number of ways to give 16 different things to A, B, C so that B gets 1...

    Text Solution

    |

  15. The number of ways in which and examiner can assign 20 maks to...

    Text Solution

    |

  16. The number of ways in which 13 gold coins can be distributed ...

    Text Solution

    |

  17. IF there are 6 periods in each working day of a school , then ...

    Text Solution

    |

  18. The number of 5 digited numbers using all the digits 2, 4, 6, 8 is

    Text Solution

    |

  19. The number of 4 letter words can be formed from the letters of the wor...

    Text Solution

    |

  20. There are 12 boys to be seated on 2 benches , 6 on each lenc...

    Text Solution

    |