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**Mathegocart****Member**- Registered: 2012-04-29
- Posts: 1,960

1. The sum of the first 2 terms of an geometric series is 7. The sum of the first 6, however, is 91. What is the sum of the first 4 terms?

2. Find the sum of .(Please put your solution in fractional forme.)

3. By adding the same constant A to 20, 50 and 100, a geometric progression results. Find the common ratio and the constant A.

4. The first three numbers of a set A form a arithmetic progression. The last three form a geometric progression. The sum of the first and last elements of A is 16. The sum of the middle two numbers is 12.Find these 4 elements, but be warned that there is more than one solution. BONUS to anyone who finds both of them.

All elements of A are integers.

5. The sum of the first 2011 terms of a GEOMETRIC PROGRESSION is 200. The sum of the first 4022, however, is 380, Find the sum of the first 6033 terms.

6. Find the coefficient of the term that contains x^4 in the expansion of

7. Find the least positive integer whose digits add to a multiple of 27 yet the number itself is not a multiple

of 27. For example, 87999921 is one such number.

8.How many non-congruent isosceles triangles (including equilateral triangles) have positive integer side

lengths and perimeter less than 20?

9. The Bobbym Lizard Garden Store sells grass seed in ten-pound bags and fifteen-pound bags. Yesterday half

of the grass seed they had was in ten-pound bags. This morning the store received a shipment of 27 more

ten-pound bags, and now they have twice as many ten-pound bags as fifteen-pound bags. Find the total

weight in pounds of grass seed the store now has.

10. The zeros of the function f(x) = x^2-ax+3a are integers. What is the sum of the possible values of a. If there are NONE, respond with NONE.

The integral of hope is reality.

May bobbym have a wonderful time in the pearly gates of heaven.

He will be sorely missed.

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**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606

Hi;

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

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**Mathegocart****Member**- Registered: 2012-04-29
- Posts: 1,960

bobbym wrote:

Hi;

Hello, I vastly disagree with you on 1, I could not get a negative solution.

Well done, and a is indeed an integer.

The integral of hope is reality.

May bobbym have a wonderful time in the pearly gates of heaven.

He will be sorely missed.

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**thickhead****Member**- Registered: 2016-04-16
- Posts: 1,086

*Last edited by thickhead (2016-09-01 05:36:58)*

**{1}Vasudhaiva Kutumakam.{The whole Universe is a family.}(2)Yatra naaryasthu poojyanthe Ramanthe tatra Devataha{Gods rejoice at those places where ladies are respected.}**

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**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606

Hello, I vastly disagree with you on 1,

People who disagree with me are eaten by gators, which seems fair.

I am sticking with the answer for one. There is also another answer for one which I did not put down.

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

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**Mathegocart****Member**- Registered: 2012-04-29
- Posts: 1,960

thickhead wrote:

Well done, thickhead, but I am getting a similar but different answer. Let me verify mine again..

The integral of hope is reality.

May bobbym have a wonderful time in the pearly gates of heaven.

He will be sorely missed.

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**Mathegocart****Member**- Registered: 2012-04-29
- Posts: 1,960

bobbym wrote:

Hello, I vastly disagree with you on 1,

People who disagree with me are eaten by gators, which seems fair.

I am sticking with the answer for one. There is also another answer for one which I did not put down.

Bobbym, I know you fear your nefarious lizard neighbors so I will infest your house with lizards.

May bobbym have a wonderful time in the pearly gates of heaven.

He will be sorely missed.

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**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606

I have a little lizard running around there right now. It is about three inches long and very fast. It came in when I opened the door about a month ago. I thought he found his way out but he is still in here.

28 is the other answer but the -21, that was the hard one.

Filled in a few more, check post #2.

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

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**thickhead****Member**- Registered: 2016-04-16
- Posts: 1,086

**{1}Vasudhaiva Kutumakam.{The whole Universe is a family.}(2)Yatra naaryasthu poojyanthe Ramanthe tatra Devataha{Gods rejoice at those places where ladies are respected.}**

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**thickhead****Member**- Registered: 2016-04-16
- Posts: 1,086

I chose common ratio r=sqrt(3) since I thought it would suit the irrational personality of Mathegocart.

But bobbym thought otherwise and chose r=2*sqrt(-1) as he thought there is nothing real but only imaginary value present in Mathegocart.

**{1}Vasudhaiva Kutumakam.{The whole Universe is a family.}(2)Yatra naaryasthu poojyanthe Ramanthe tatra Devataha{Gods rejoice at those places where ladies are respected.}**

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**thickhead****Member**- Registered: 2016-04-16
- Posts: 1,086

(2)Yatra naaryasthu poojyanthe Ramanthe tatra Devataha

{Gods rejoice at those places where ladies are respected.}

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**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606

There are actually 6 values for a:

{-4, -4, 0, 12, 16, 16}

each one corresponding to a different x. I decided to use the double -4 and 16 in the sum. That is where I got 36. I could not deduce from the question whether doubles were to be considered or not because no where in the question does it say distinct a's. Now, looking at the question and having to guess what Mathegocart wants I would go with 24 too.

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

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**thickhead****Member**- Registered: 2016-04-16
- Posts: 1,086

I missed nothing in the total but curiously I missed a=0!

(2)Yatra naaryasthu poojyanthe Ramanthe tatra Devataha

{Gods rejoice at those places where ladies are respected.}

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**Mathegocart****Member**- Registered: 2012-04-29
- Posts: 1,960

thickhead wrote:

I chose common ratio r=sqrt(3) since I thought it would suit the irrational personality of Mathegocart.

But bobbym thought otherwise and chose r=2*sqrt(-1) as he thought there is nothing real but only imaginary value present in Mathegocart.

Irrational? My profound eccentricity is only relative to yours!

I am not real nor imaginary, I am truly complex.

Also I see you have adapted my signature into a more adept one. Too bad there is no LaTeX implementation in the sigs, for it would make for quite a grandeur look!

*Last edited by Mathegocart (2016-09-02 04:19:08)*

May bobbym have a wonderful time in the pearly gates of heaven.

He will be sorely missed.

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**Mathegocart****Member**- Registered: 2012-04-29
- Posts: 1,960

bobbym wrote:

There are actually 6 values for a:

{-4, -4, 0, 12, 16, 16}

each one corresponding to a different x. I decided to use the double -4 and 16 in the sum. That is where I got 36. I could not deduce from the question whether doubles were to be considered or not because no where in the question does it say distinct a's. Now, looking at the question and having to guess what Mathegocart wants I would go with 24 too.

That was the intended solution(24.)

May bobbym have a wonderful time in the pearly gates of heaven.

He will be sorely missed.

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**thickhead****Member**- Registered: 2016-04-16
- Posts: 1,086

Mathegocart wrote:

Well done, thickhead, but I am getting a similar but different answer. Let me verify mine again..

Where do we differ?

(2)Yatra naaryasthu poojyanthe Ramanthe tatra Devataha

{Gods rejoice at those places where ladies are respected.}

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**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606

All done then?

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

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**Mathegocart****Member**- Registered: 2012-04-29
- Posts: 1,960

thickhead wrote:

Mathegocart wrote:Well done, thickhead, but I am getting a similar but different answer. Let me verify mine again..

Where do we differ?

(5)

May bobbym have a wonderful time in the pearly gates of heaven.

He will be sorely missed.

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**Mathegocart****Member**- Registered: 2012-04-29
- Posts: 1,960

Note: I am planning to develop a formidable armada of physics questions.

May bobbym have a wonderful time in the pearly gates of heaven.

He will be sorely missed.

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**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606

A formidable armada? You have a very good vocabulary.

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

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**thickhead****Member**- Registered: 2016-04-16
- Posts: 1,086

*Last edited by thickhead (2016-09-02 16:42:11)*

(2)Yatra naaryasthu poojyanthe Ramanthe tatra Devataha

{Gods rejoice at those places where ladies are respected.}

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**thickhead****Member**- Registered: 2016-04-16
- Posts: 1,086

Hi Mathegocart,

I have to admit I am a nut. My method was too long.In A.P. Groups of terms of same size are also in A.P.

(5)sum of 1st 2011 terms=200

sum of next 2011 terms=380-200=180 D=180 -200 =-20

sum of next 2011 terms=180 -20=160

Sum of first 6033 terms=200 +180+160=540

*Last edited by thickhead (2016-09-02 18:19:12)*

(2)Yatra naaryasthu poojyanthe Ramanthe tatra Devataha

{Gods rejoice at those places where ladies are respected.}

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**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606

Hi;

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

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**thickhead****Member**- Registered: 2016-04-16
- Posts: 1,086

hi bobbym,

Does Mathegocart agree with you? I have to fight in 2 fronts even if he does not agree with you and not with me also.

Cn=an you find holes in the 2 methods I have described?

(2)Yatra naaryasthu poojyanthe Ramanthe tatra Devataha

{Gods rejoice at those places where ladies are respected.}

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**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606

I do not know what Mr. Mathegocart has for an answer yet.

Are you solving for geometric progressions?

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

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