Home
Class 11
MATHS
The value of sum(r=1)^n (^nPr)/(r!) is...

The value of `sum_(r=1)^n (^nP_r)/(r!)` is

A

`2^n`

B

`2^n-1`

C

`2^(n-1)`

D

`2^n+1`

Text Solution

Verified by Experts

The correct Answer is:
B
Promotional Banner

Topper's Solved these Questions

  • PERMUTATION AND COMBINATION

    PATHFINDER|Exercise QUESTION BANK|223 Videos

  • PRINCIPLE OF MATHEMATICAL INDUCTION AND LINEAR INEQUATIONS

    PATHFINDER|Exercise QUESTION BANK|14 Videos

Similar Questions

Explore conceptually related problems

The value of sum_(r=0)^(n-1) (""^nC_r)/(""^nC_r+ ""^n C_(r+1)) equals a. n+1 b. n/2 c. n+2 d. none of these

Find the value of sum_(r=1)^(n) (r)/(1+r^(2)+r^(4))

The value of sum_(r=1)^(n)(-1)^(r-1)((r )/(r+1))*^(n)C_(r ) is (a) 1/(n+1) (b) 1/n (c) 1/(n-1) (d) 0

The value of sum_(r=1)^n(sum_(p=0)^(r-1) ^nC_r ^rC_p 2^p) is equal to (a) 4^(n)-3^(n)+1 (b) 4^(n)-3^(n)-1 (c) 4^(n)-3^(n)+2 (d) 4^(n)-3^(n)

The value of sum_(r=1)^(n) (-1)^(r+1)(""^(n)C_(r))/(r+1) is equal to

If (4x^(2) + 1)^(n) = sum_(r=0)^(n)a_(r)(1+x^(2))^(n-r)x^(2r) , then the value of sum_(r=0)^(n)a_(r) is

The value of sum_(r=1)^(5)(i^(r )-i^(r+1)) is, where i=sqrt(-1)

The value of sum_(r=1)^(n+1)(sum_(k=1)^n ^kC_(r-1)) (where r, k, n in N ) is equal to

Find the sum of sum_(r=1)^n r* (nC_r)/(nC_(r-1)

The value of sum_(r=1)^(49)(2r^(2) - 48r +1)/((50-r).""^(50)C_(r)) is "_____" .

PATHFINDER-PERMUTATION AND COMBINATIONS-QUESTION BANK
  1. If ^9P5=x^9P3 then the value of x will be

    Text Solution

    |

  2. If ^nPr=^nP(r+1) and ^nCr=^nC(r-1) then the values of n,r are

    Text Solution

    |

  3. The value of sum(r=1)^n (^nPr)/(r!) is

    Text Solution

    |

  4. Let Tn denote of the number of triangles which can be formed using the...

    Text Solution

    |

  5. The number of parallelograms that can be formed from a set of four par...

    Text Solution

    |

  6. A polygon has 44 diagonals the number of sides of the polygon is

    Text Solution

    |

  7. In a room each person present shakes hand with the other . If the tota...

    Text Solution

    |

  8. The value of : ^15C1 +^15C3 + ^15C5+…..+ ^15C15 is

    Text Solution

    |

  9. The number of 10 digit numbers formed by using the digits 1&2 is

    Text Solution

    |

  10. The maximum number of trials to open n locks by n keys is 105. Then n...

    Text Solution

    |

  11. The number of circles that can be drawn out of 10 points of which 7 ar...

    Text Solution

    |

  12. The number of different 6-digit numbers that can be formed using the t...

    Text Solution

    |

  13. The number of ways in which 6 different balls can be put in two boxes ...

    Text Solution

    |

  14. If 7 points out of 12 are in same st. line the number of triangles for...

    Text Solution

    |

  15. The total number of 9 digit numbers which have all different digit is

    Text Solution

    |

  16. The number of ways in which 5 letters can be posted in 10 letter boxes...

    Text Solution

    |

  17. The number of five digit telephone numbers none of their digits being ...

    Text Solution

    |

  18. There are 13 stations on a certain railway line.How many kinds of diff...

    Text Solution

    |

  19. Prove that (2n!)/(n!)={1.3.5.....(2n-1)}2^n

    Text Solution

    |

  20. Find the number of diagonals in a polygon with n sides.

    Text Solution

    |