Home
Class 12
MATHS
IF ""^(n)P(r)=840,""^(n)C(r)=35 then ...

IF `""^(n)P_(r)=840,""^(n)C_(r)=35 ` then n=

A

1

B

7

C

4

D

10

Text Solution

Verified by Experts

The correct Answer is:
B
Promotional Banner

Topper's Solved these Questions

  • MOCK TEST 2

    SIA PUBLICATION|Exercise Physics|15 Videos

  • MOCK TEST 2

    SIA PUBLICATION|Exercise Chemistry|21 Videos

  • MOCK TEST 1

    SIA PUBLICATION|Exercise PHYSICS|12 Videos

  • PAIR OF STRAIGHT LINES

    SIA PUBLICATION|Exercise PROBLEM|42 Videos

Similar Questions

Explore conceptually related problems

IF ""^(n) P_(r)=720,""^(n)C_(r)=120 then (n,r) =

If ""^(n)P_(r)=30240 and ""^(n)C_(r)=252 then the ordered pair (n,r)=

IF ""^(n) C_((r-1))=36 ,""^(n)C_(r)=84 , ""^(n)C_(r+1)=126 , then r=

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

I : IF ""^(n+1) P_(5) : ""^(n)P_(5)=3:2 then n=14 . II . IF ""^(56)P_(r-6) : ""^(56)P_(r+3)=30800 : 1 then r= 41.

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

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

If ""^(n)P_(r)=5040 and ""^(n)C_(r)=210, find n and r.

If ""^(n)P_(r)=5040 and ""^(n)C_(r)=210 , find n and r.

SIA PUBLICATION-MOCK TEST 2-Chemistry
  1. IF ""^(n)P(r)=840,""^(n)C(r)=35 then n=

    Text Solution

    |

  2. A metallic carbide on treatment with water gives a colourless gas whic...

    Text Solution

    |

  3. Chlorination of toluene in presence of light and heat followed by trea...

    Text Solution

    |

  4. Molar ionic conductivities of a bivalent electrolyte are 57 and 73. Th...

    Text Solution

    |

  5. The forces operating between the adsorbate and the adsorbent in physic...

    Text Solution

    |

  6. Horn silver is

    Text Solution

    |

  7. Stainless steel does not rust because

    Text Solution

    |

  8. A polymer which is commonly used as a packaging material is

    Text Solution

    |

  9. Which compound/set of compounds is used in the manufacture of Nylon-6,...

    Text Solution

    |

  10. The pH value of a solution in which a polar amino acid does not migrat...

    Text Solution

    |

  11. The substances which affect the central nervous system and induce slee...

    Text Solution

    |

  12. Which is detected by carbylamine test?

    Text Solution

    |

  13. Acid catalyzed hydration of alkenes except ethane leads to the formati...

    Text Solution

    |

  14. 2, 2-dichloro propane treated with aq.KOH gives an unstable product. I...

    Text Solution

    |

  15. The process that does not yield an amine is

    Text Solution

    |

  16. Which one of the following compounds would undergo nitration with grea...

    Text Solution

    |

  17. In the chemical reaction, CH(3)CH(2)NH(2) + CHCl(3) + 3KOH rarr (A)+ (...

    Text Solution

    |

  18. X' grams of calcium carbonate was completely burnt in air. The weight ...

    Text Solution

    |

  19. 4 g of a hydrocarbon on complete combustion gave 12.571 g of Co, and 5...

    Text Solution

    |

  20. 10 grams of CaCO(3) is completely decomposed to x and CaO. 'x' is pass...

    Text Solution

    |

  21. 50 grams of calcium carbonate was completely burnt in air. What is the...

    Text Solution

    |