Home
Class 12
MATHS
If a1, a2, a3, be terms of an A.P. and ...

If `a_1, a_2, a_3, ` be terms of an A.P. and `(a_1+a_2+.....+a_p)/(a_1+a_2+.....+a_q)=(p^2)/(q^2), p!=q ,t h e n(a_6)/(a_(21))` equals to (a).41/11`` (b). 7/2`` (c). 2/7`` (d). 11/41

A

`(41)/(11)`

B

`(7)/(2)`

C

`(2)/(7)`

D

`(11)/(41)`

Text Solution

Verified by Experts

The correct Answer is:
D

`:.((p)/(2)[2a_(1)+(p-1)d])/((q)/(2)[2a_(1)+(q-1)d])=(p^(2))/(q^(2))`
`implies (2a_(1)+(p-1)d)/(2a_(1)+(q-1)d)=(p)/(q)implies (a_(1)+((p-1)/(2))d)/(a_(1)+((q-1)/(2))d)=(p)/(q)`
For `(a_(6))/(a_(21)),p=11" and " q=41 implies(a_(6))/(a_(21))=(11)/(41)`.
Promotional Banner

Topper's Solved these Questions

  • SEQUENCES AND SERIES

    ARIHANT MATHS ENGLISH|Exercise Exercise (Subjective Type Questions)|24 Videos
  • PROPERTIES AND SOLUTION OF TRIANGLES

    ARIHANT MATHS ENGLISH|Exercise Exercise (Questions Asked In Previous 13 Years Exam)|21 Videos
  • SETS, RELATIONS AND FUNCTIONS

    ARIHANT MATHS ENGLISH|Exercise Exercise (Questions Asked In Previous 13 Years Exam)|12 Videos

Similar Questions

Explore conceptually related problems

Let a_1,a_2,a_3,...... be an A.P. such that [a_1+a_2+......+a_p]/[a_1+a_2+a_3+......+a_q]=p^3/q^3 ; p!=q .Then a_6/a_[21] is equal to:

If a_1, a_2, a_3,.....a_n are in H.P. and a_1 a_2+a_2 a_3+a_3 a_4+.......a_(n-1) a_n=ka_1 a_n , then k is equal to

If a_1,a_2,a_3,...,a_(n+1) are in A.P. , then 1/(a_1a_2)+1/(a_2a_3)....+1/(a_na_(n+1)) is

If a_1,a_2,a_3,……a_n are in A.P. [1/(a_1a_n)+1/(a_2a_(n-1))+1/(a_3a_(n-2))+..+1/(a_na_1)]

a_1,a_2, a_3, ,a_n are in A.P. and a_1+a_3+a_5+a_7+a_9=20 then a_5 is 2 2. 7 3. 3 4. 4 5. 5

Let a_1,a_2 ,a_3 …..be in A.P. and a_p, a_q , a_r be in G.P. Then a_q : a_p is equal to :

Let a_1, a_2, a_3, ...a_(n) be an AP. then: 1 / (a_1 a_n) + 1 / (a_2 a_(n-1)) + 1 /(a_3a_(n-2))+......+ 1 /(a_(n) a_1) =

If a_1,a_2,……….,a_n are in H.P. then expression a1a2+a2a3+......+a_n-1an

If a_1,a_2,a_3….a_(2n+1) are in A.P then (a_(2n+1)-a_1)/(a_(2n+1)+a_1)+(a_2n-a_2)/(a_(2n)+a_2)+....+(a_(n+2)-a_n)/(a_(n+2)+a_n) is equal to

Let a_1, a_2, a_3.......... be in A.P. and h_1,h_2,h_3..... ,in H.P. If a_1=2 = h_1, and a_30=25=h_30 then a_7h_24+ a_14 + a_17=

ARIHANT MATHS ENGLISH-SEQUENCES AND SERIES-Exercise (Questions Asked In Previous 13 Years Exam)
  1. Let a,b,c be in A.P. and |a|lt1,|b|lt1|c|lt1.ifx=1+a+a^(2)+ . . . ."to...

    Text Solution

    |

  2. about to only mathematics

    Text Solution

    |

  3. If a1, a2, a3, be terms of an A.P. and (a1+a2+.....+ap)/(a1+a2+.....+...

    Text Solution

    |

  4. If a1, a2, a3,.....an are in H.P. and a1 a2+a2 a3+a3 a4+.......a(n-1...

    Text Solution

    |

  5. Let V(r ) denotes the sum of the first r terms of an arithmetic progre...

    Text Solution

    |

  6. Let Vr denote the sum of the first r terms of an arithmetic progressio...

    Text Solution

    |

  7. Let V(r) denote the sum of the first r terms of an arithmetic progress...

    Text Solution

    |

  8. LetA(1),G(1),H(1) denote the arithmetic, geometric and harmonic means ...

    Text Solution

    |

  9. Let A1 , G1, H1denote the arithmetic, geometric and harmonic means re...

    Text Solution

    |

  10. LetA(1),G(1),H(1) denote the arithmetic, geometric and harmonic means ...

    Text Solution

    |

  11. In a G.P of positive terms if any term is equal to the sum of the next...

    Text Solution

    |

  12. Suppose four distinct positive numbers a(1),a(2),a(3),a(4) are in G.P....

    Text Solution

    |

  13. The first two terms of a geometric progression add up to 12. The sum o...

    Text Solution

    |

  14. If the sum of first n terms of an A.P. is cn^(2) then the sum of squar...

    Text Solution

    |

  15. The sum to infinity of the series 1+2/3+6/3^2+14/3^4+...is

    Text Solution

    |

  16. Let Sk,k=1, 2, …. 100 denote the sum of the infinite geometric series ...

    Text Solution

    |

  17. Let a1, a2, a3, ,a(11) be real numbers satisfying a1=15 , 27-2a2>0 a ...

    Text Solution

    |

  18. A person is to count 4500 currency notes. Let an denote the number of ...

    Text Solution

    |

  19. The minimum value of the sum of real numbers a^-5, a^-4, 3a^-3, 1,a^8 ...

    Text Solution

    |

  20. A man saves ₹ 200 in each of the first three months of his servies.In ...

    Text Solution

    |