Home
Class 11
MATHS
Find the sum of first 20 terms of an A.P...

Find the sum of first 20 terms of an A.P., in which `3r d` terms in 7 and `7t h` term is tow more than thrice of its `3r d` term.

Text Solution

AI Generated Solution

Promotional Banner

Topper's Solved these Questions

  • BINOMIAL THEOREM

    RD SHARMA ENGLISH|Exercise All Questions|228 Videos

Similar Questions

Explore conceptually related problems

Find the sum of first 20 terms of an A.P., in which 3rd term is 7 and 7th term is two more than thrice of its 3rd term.

Find the sum of first 20 terms of an A.P. whose first term is 3 and the last term is 57.

Find the sum of 20 terms of the A.P. 1,4,7,10…..

Find the sum of the first 25 terms of an A.P. whose n t h term is given by a_n=7-3n .

Find the sum of the first 25 terms of an A.P. whose n t h term is given by a_n=2-3n .

If the sum of first n terms of an A.P. is 3n^2 + 2n , find its r^(th) term.

The sum of first n terms of an A.P. is 3n^2+4n . Find the 25 t h term of this A.P.

If the sum of first 7 terms of an AP is 49 and that of 17 terms is 289, find the sum of first n terms.

If the sum of first 7 terms of an AP is 49 and that of 17 terms is 289, find the sum of first n terms.

If the sum of first 7 terms of an AP is 49 and that of 17 terms is 289, find the sum of first n terms.

RD SHARMA ENGLISH-ARITHMETIC PROGRESSIONS-All Questions
  1. The internal angles of quadrilateral are in A.P. and their common diff...

    Text Solution

    |

  2. Find the sum of all natural between 250 and 1000 which are exactly ...

    Text Solution

    |

  3. Find the sum of first 20 terms of an A.P., in which 3r d terms in 7 an...

    Text Solution

    |

  4. Find the number of terms in the series 20 ,19 1/3,18 2/3... the sum of...

    Text Solution

    |

  5. The sums of n terms of three arithmetical progressions are S1, S2and ...

    Text Solution

    |

  6. If in an A.P. the sum of m terms is equal of n and the sum of n ter...

    Text Solution

    |

  7. The first , second and the last terms of an A.P. are a ,b , c respect...

    Text Solution

    |

  8. If (3+5+7+ u p tont e r m s)/(5+8+11+ u p to10t e r m s)=7, then find...

    Text Solution

    |

  9. In a factory, 150 workers were engaged to finish a piece of work in a ...

    Text Solution

    |

  10. Prove that the sum of n arithmetic means between two numbers in n ti...

    Text Solution

    |

  11. If a ,b ,c are in A.P., then prove that: (a – c)^2 = 4(b^2 – ac).

    Text Solution

    |

  12. If a^2(b+c),b^2(c+a),c^2(a+b), are in A.P. show that either a ,b ,c ar...

    Text Solution

    |

  13. If n arithemetic means are inserted between 20 and 80 such that the ra...

    Text Solution

    |

  14. Along a road lie an odd number of stones placed at intervals of 10 met...

    Text Solution

    |

  15. A carpenter was hired to build 192 window frames. The first day he mad...

    Text Solution

    |

  16. In a potato race 20 potatoes are placed in a line at intervals of 4m e...

    Text Solution

    |

  17. We know that the sum of the interior angles of a triangle is180^0 . S...

    Text Solution

    |

  18. If S1 be the sum of (2n+1) term of an A.P. and S2 be the sum of its od...

    Text Solution

    |

  19. Divide 32 into four parts which are in A.P. such that the product of ...

    Text Solution

    |

  20. If theta1,theta2,theta3, ,thetan are in AP, whose common difference ...

    Text Solution

    |