Home
Class 11
MATHS
Find the number of ways in which 10 cond...

Find the number of ways in which 10 condidates `A_(1),A_(2),......,A_(10)` can be ranked so that `A_(1)` is always above `A_(2)`,

A

10!

B

`(10!)/(2)`

C

9!

D

none of these

Text Solution

Verified by Experts

Ten candidates can be ranked in 10! ways. In half of these ways A1 is above `A_(2)` and in another half `A_(2)` is above `A_(1)`. So, required number of ways `=(10!)/(2)`
Promotional Banner

Topper's Solved these Questions

  • PERMUTATIONS AND COMBINATIONS

    OBJECTIVE RD SHARMA ENGLISH|Exercise Section II - Assertion Reason Type|9 Videos

  • PERMUTATIONS AND COMBINATIONS

    OBJECTIVE RD SHARMA ENGLISH|Exercise Exercise|136 Videos

  • PERMUTATIONS AND COMBINATIONS

    OBJECTIVE RD SHARMA ENGLISH|Exercise Chapter Test|60 Videos

  • PARABOLA

    OBJECTIVE RD SHARMA ENGLISH|Exercise Chapter Test|30 Videos

  • PROBABILITY

    OBJECTIVE RD SHARMA ENGLISH|Exercise Chapter Test|45 Videos

Similar Questions

Explore conceptually related problems

The number of ways in which 10 candidates A_1,A_2, A_(10) can be ranked such that A_1 is always above A_(10) is a. 5! b. 2(5!) c. 10 ! d. 1/2(10 !)

, the number of ways in which 10 candidates A_(1)andA_(2) can be ranked if if A1 is always above A2

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

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

The number of functions from f:{a_(1),a_(2),...,a_(10)} rarr {b_(1),b_(2),...,b_(5)} is

The number of all possible 5-tuples (a_(1),a_(2),a_(3),a_(4),a_(5)) such that a_(1)+a_(2) sin x+a_(3) cos x + a_(4) sin 2x +a_(5) cos 2 x =0 hold for all x is

If A_(1),A_(2) are between two numbers, then (A_(1)+A_(2))/(H_(1)+H_(2)) is equal to

Let a_(1),a_(2),.......,a_(n) be fixed real numbers and define a function f(x)=(x-a_(1))(x-a_(2)) ......(x-a_(n)) , what is lim f(x) ? For some anea_(1),a_(2),.........a_(n) , compute lim_(Xrarr1) f(x)

If a_(1),a_(2),a_(3),"........" is an arithmetic progression with common difference 1 and a_(1)+a_(2)+a_(3)+"..."+a_(98)=137 , then find the value of a_(2)+a_(4)+a_(6)+"..."+a_(98) .

If the coefficients of 4 consecutive terms in the expansion of (1+x)^(n) are a_(1),a_(2),a_(3),a_(4) respectively, then show that (a_(1))/(a_(1)+a_(2))+(a_(3))/(a_(3)+a_(4))=(2a_(2))/(a_(2)+a_(3))

OBJECTIVE RD SHARMA ENGLISH-PERMUTATIONS AND COMBINATIONS-Section I - Solved Mcqs
  1. The number of 5-digit number that can be made using the digits 1 and 2...

    Text Solution

    |

  2. The number of ways of dividing 20 persons into 10 couples is

    Text Solution

    |

  3. Find the number of ways in which 10 condidates A(1),A(2),......,A(10) ...

    Text Solution

    |

  4. There are n white and n black balls marked 1, 2, 3,…..,n. The number o...

    Text Solution

    |

  5. The number of ways in which we can distribute m n students equally ...

    Text Solution

    |

  6. The total number of 6-digit numbers in which the sum of the digits is ...

    Text Solution

    |

  7. The number of integers solutions for the equation x+y+z+t=20, where x,...

    Text Solution

    |

  8. The number of integral solutions of x+y+z=0 with xgeq-5,ygeq-5,zgeq-5 ...

    Text Solution

    |

  9. The number of non-negative integral solutions of x+y+z<=n, where n in ...

    Text Solution

    |

  10. If n objects are arrange in a row, then the number of ways of select...

    Text Solution

    |

  11. There are three piles of identical red, blue and green balls and each ...

    Text Solution

    |

  12. If n objects are arrange in a row, then the number of ways of select...

    Text Solution

    |

  13. Between two junction stations A and B there are 12 intermediate statio...

    Text Solution

    |

  14. In how many ways can 30 marks be allotted to 8 question if each que...

    Text Solution

    |

  15. The number of points in space, whose each co-ordinate is a negative in...

    Text Solution

    |

  16. If x,y,z is integer and xge0,yge1,zge2,x+y+z=15 then the number of va...

    Text Solution

    |

  17. If a, b, c, are natural numbers in AP and then the possible number of...

    Text Solution

    |

  18. If x, y, z, t are odd natural numbers such that x + y + z +w=20 then ...

    Text Solution

    |

  19. The number of ways in which a score of 11 can be made from a through t...

    Text Solution

    |

  20. The sum of all the numbers of four different digits that can be mad...

    Text Solution

    |