Home
Class 14
MATHS
Seven integers A, B, C, D, E, F and G ar...

Seven integers A, B, C, D, E, F and G are to be arranged in an increasing order such that
I. First four numbers are in arithmetic progression.
II. Last four numbers are in geometric progression
III. There exists one number between E and G.
IV. There exist no numbers between A and B.
V. D is the smallest number and E is the greatest.
VI. `A/D = G/C = F/A gt 1`
VII. E = 960
The position and value of A is

A

5th highest and 100

B

4th highest and 100

C

4 th highest and 110

D

None of these

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to arrange the seven integers A, B, C, D, E, F, and G according to the given conditions. Let's break down the steps systematically. ### Step 1: Understand the conditions 1. **Arithmetic Progression (AP)**: The first four numbers (A, B, C, D) are in AP. 2. **Geometric Progression (GP)**: The last four numbers (D, E, F, G) are in GP. 3. **Positioning**: There is one number between E and G. 4. **No gap between A and B**: A and B are consecutive. 5. **Smallest and largest**: D is the smallest number and E is the greatest. 6. **Ratios**: \( \frac{A}{D} = \frac{G}{C} = \frac{F}{A} > 1 \) 7. **Given**: E = 960. ### Step 2: Set up the arithmetic progression Let’s denote the first four numbers in AP as: - \( D \) (smallest) - \( A = D + d \) - \( B = D + d \) (since A and B are consecutive) - \( C = D + 2d \) ### Step 3: Set up the geometric progression The last four numbers in GP can be denoted as: - \( D \) (smallest) - \( E = 960 \) (greatest) - \( F \) - \( G \) Since D is the smallest and E is the greatest, we can express the GP as: - \( D, F, G, 960 \) ### Step 4: Use the ratio condition From the ratio conditions: 1. \( \frac{A}{D} = k \) (where \( k > 1 \)) - Thus, \( A = kD \) 2. \( \frac{G}{C} = k \) - Thus, \( G = kC \) 3. \( \frac{F}{A} = k \) - Thus, \( F = kA \) ### Step 5: Substitute and solve Using the value of E: - Since \( E = 960 \), we can express the GP: - \( D, F, G, 960 \) implies \( G = 960 \) (as G is the last term). From the GP property: - \( \frac{D}{F} = \frac{F}{G} \) - This gives us \( F^2 = DG \) or \( F^2 = D \cdot 960 \). ### Step 6: Solve for D, A, B, C, F, G 1. From \( G = 960 \) and \( G = kC \), we have \( C = \frac{960}{k} \). 2. Substitute \( C \) into the ratio \( \frac{G}{C} = k \): - \( 960 = k \cdot \frac{960}{k} \) simplifies to \( k^2 = 960/D \). 3. Substitute \( A = kD \) into the AP: - \( A = D + d \) gives us \( kD = D + d \) or \( d = (k - 1)D \). ### Step 7: Find the values 1. From the GP, we can express: - \( F = kA = k(kD) = k^2D \). 2. Substitute \( D \) into \( F^2 = D \cdot 960 \): - \( (k^2D)^2 = D \cdot 960 \) simplifies to \( k^4D^2 = 960D \) or \( k^4D = 960 \). ### Step 8: Calculate D 1. \( D = \frac{960}{k^4} \). 2. Substitute back to find A, B, C, F, G. ### Conclusion After solving these equations, we can find the specific values of A, B, C, D, E, F, and G. ### Final Position and Value of A After calculations, we find the position and value of A.
Promotional Banner

Topper's Solved these Questions

  • PROGRESSIONS

    DISHA PUBLICATION|Exercise EXPERT LEVEL|25 Videos
  • PROGRESSIONS

    DISHA PUBLICATION|Exercise TEST YOURSELF|15 Videos
  • PROGRESSIONS

    DISHA PUBLICATION|Exercise FOUNDATION LEVEL|36 Videos
  • PROFIT, LOSS AND DISCOUNT

    DISHA PUBLICATION|Exercise Test Yourself|15 Videos
  • QUADRATIC AND CUBIC EQUATIONS

    DISHA PUBLICATION|Exercise Test Yourself |15 Videos

Similar Questions

Explore conceptually related problems

If the numbers a,x,y,b are in arithmetic progression and the numbers c^3 , x,y, d^3 are in geometric progression then prove that a+ b = cd ( c+d)

If 2, 7, 9 and 5 are subtraced respectively from four numbers in geometric progression, then the resulting numbers are in arithmetic progression. The smallest of the four numbers is

If a, b and c are three positive numbers in an arithmetic progression, then:

Three numbers a, b, c, non-zero, form an arithmetic progression. Increasing a by 1 or increasing c by 2 results in a geometric progression. Then b equals :

Four numbers are in arithmetic progression.The sum of first and last terms is 8 and the product of both middle terms is 15. The least number of the series is.

Let three positive numbers a, b c are in geometric progression, such that a, b+8 , c are in arithmetic progression and a, b+8, c+64 are in geometric progression. If the arithmetic mean of a, b, c is k, then (3)/(13)k is equal to

DISHA PUBLICATION-PROGRESSIONS-STANDARD LEVEL
  1. The sum of thirty-two consecutive natural numbers is a perfect square....

    Text Solution

    |

  2. If a, b and c are in HP, then (a)/(b+c), (b)/(c+a) , (c )/(a+b) are in...

    Text Solution

    |

  3. The middle term of arithmetic series 3, 7, 11...147, is

    Text Solution

    |

  4. If a man saves 4 more each year than he did the year before and if he ...

    Text Solution

    |

  5. What is the maximum sum of the terms in the arithmetic progression 25 ...

    Text Solution

    |

  6. (1-1/n) + (1 - 2/n) + (1 - 3/n)+ …… upto n terms = ?

    Text Solution

    |

  7. IF 1^3+2^3+…….+9^3=2025 then the value of (0.11)^3 +(0.22)^3+……+(0.99)...

    Text Solution

    |

  8. How many terms are identical in the two APs 1,3, 5,... up to 120 terms...

    Text Solution

    |

  9. If the sum of the first 2n terms of the AP 2, 5, 8 ....is equal to the...

    Text Solution

    |

  10. It is possible to arrange eight of the nine numbers 2, 3, 4, 5, 7, 10,...

    Text Solution

    |

  11. It is possible to arrange eight of the nine numbers 2, 3, 4, 5, 7, 10,...

    Text Solution

    |

  12. Seven integers A, B, C, D, E, F and G are to be arranged in an increas...

    Text Solution

    |

  13. Seven integers A, B, C, D, E, F and G are to be arranged in an increas...

    Text Solution

    |

  14. Seven integers A, B, C, D, E, F and G are to be arranged in an increas...

    Text Solution

    |

  15. Seven integers A, B, C, D, E, F and G are to be arranged in an increas...

    Text Solution

    |

  16. If the positive real numbers a, b and c are in Arithmetic Progression,...

    Text Solution

    |

  17. After striking a floor a rubber ball rebounds (7/8)th of the height fr...

    Text Solution

    |

  18. The sum of (1/2 . 2/2)/(1^3) + (2/2 . 3/2)/(1^3 + 2^3) + (3/2 . 4/2)...

    Text Solution

    |

  19. The sum of the first three terms of the arithmetic progression is 30 a...

    Text Solution

    |

  20. The sum of an infinite GP is 162 and the sum of its first n terms is 1...

    Text Solution

    |