Home
Class 12
MATHS
If ""^(n)C(r) +""^(n) C(r+1)= ""^((n+1))...

If `""^(n)C_(r) +""^(n) C_(r+1)= ""^((n+1)) C_(x)` then x=

A

r

B

r-1

C

n

D

r+1

Text Solution

Verified by Experts

The correct Answer is:
D
Promotional Banner

Topper's Solved these Questions

  • PERMUTATIONS & COMBINATIONS

    DIPTI PUBLICATION ( AP EAMET)|Exercise EXERCISE 2 ( SPECIAL TYPE QUESTIONS ) SET -1|9 Videos

  • PERMUTATIONS & COMBINATIONS

    DIPTI PUBLICATION ( AP EAMET)|Exercise EXERCISE 2 ( SPECIAL TYPE QUESTIONS ) SET -2|5 Videos

  • PERMUTATIONS & COMBINATIONS

    DIPTI PUBLICATION ( AP EAMET)|Exercise EXERCISE 1A (PERMUTATIONS )|199 Videos

  • PARTIAL FRACTIONS

    DIPTI PUBLICATION ( AP EAMET)|Exercise EXERCISE 2 SET - 4|2 Videos

  • PROBABILITY

    DIPTI PUBLICATION ( AP EAMET)|Exercise EXERCISE 2 (SPECIAL TYPE QUESTIONS) SET-4|5 Videos

Similar Questions

Explore conceptually related problems

""^(n) C_(r+1)+2""^(n)C_(r) +""^(n)C_(r-1)=

If ""^(n)P_(r)=""^(n)P_((r+1)) and ""^(n)C_(r) = ""^(n)C_(r-1), then (n,r) =

If ""^(n)C_(r-1):""^(n)C_(r):""^(n)C_(r+1)=2:4:5 then (n,r) is

If ""^(n)C_(r)=""^(n)C_(r-1) and ""^(n)P_(r+1) = 9 .""^(n)P_(r) then (n,r)=

IF ""^((n+1))C_((r+1)): ""^(n)C_(r) : ""^((n-1))C_((r-1))=11:6:3 then (n,r)=

""^(n) C_(r) + 4 . ""^(n) C_(r-1) + 6 . ""^(n) C_(r-2) + 4. ""^(n)C_(r-3) + ""^(n)C_(r-4) =

""^(2n)C_(n+1)+2. ""^(2n)C_(n) + ""^(2n) C_(n-1) =

If ""^((n+1))C_(3)+""^((n-1))C_(4)gt""^(n)C_(3) , then the minimum value of n is

If ""^(n)C_(r-1)=36,""^(n)C_(r)=84 and ""^(n)C_(r+1)=126 , then r is equal to

DIPTI PUBLICATION ( AP EAMET)-PERMUTATIONS & COMBINATIONS-EXERCISE 1B (COMBINATIONS )
  1. If n and r are integers such that 1 le r le n then n. C (n-1...

    Text Solution

    |

  2. IF n and r are positive inegers such that r le n then ""^(n) ...

    Text Solution

    |

  3. If ""^(n)C(r) +""^(n) C(r+1)= ""^((n+1)) C(x) then x=

    Text Solution

    |

  4. If ""^(15)C(4) +""^((n+5))C(5)=""^(16)C(5) then n=

    Text Solution

    |

  5. ""^(n) C(r+1)+2""^(n)C(r) +""^(n)C(r-1)=

    Text Solution

    |

  6. ""^(2n)C(n+1)+2. ""^(2n)C(n) + ""^(2n) C(n-1) =

    Text Solution

    |

  7. ""^(n) C(r) + 4 . ""^(n) C(r-1) + 6 . ""^(n) C(r-2) + 4. ""^(n)C(r...

    Text Solution

    |

  8. For 1 le r le n, the value of ""^(n)C(r) +""^(n-1) C(r) + ""^...

    Text Solution

    |

  9. IF S= overset ( m) sum "" ^(n+r ) C(k), then

    Text Solution

    |

  10. ""^(14) C(4) + overset(4) sum ( 18 - j ) C (3) =

    Text Solution

    |

  11. ""^(47 ) C(4 )+ underset( j =1) overset( 5 ) sum ""^((52- j)) C(3)...

    Text Solution

    |

  12. the value of ""^50C(4) + underset( r=1) overset( 6 ) sum ""^(56...

    Text Solution

    |

  13. sum( r=0 )^ ( 10) ( 40 -r)C (5)=

    Text Solution

    |

  14. The least value of n so that ""^(n) C(5) + ""^(n ) C(6) gt (...

    Text Solution

    |

  15. The least positive intergral value of n which satisfies the ...

    Text Solution

    |

  16. IF ""^(n) C(3) : ""^((2n-1) ) C(2) = 8 : 15 then n=

    Text Solution

    |

  17. IF ""^(n) C(3) : ""^((2n-1) ) C(2) = 8 : 15 then n=

    Text Solution

    |

  18. IF C (2n, 3) : C (n,2) = 12 : 1, then n=

    Text Solution

    |

  19. If ""^(2n ) C(3) : ""^(n) C(2) = 44 : 3 then n=

    Text Solution

    |

  20. If ""^(n ) C (3) : ""^(n) C(2) = 10 : 3 , then n=

    Text Solution

    |