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**ganesh****Moderator**- Registered: 2005-06-28
- Posts: 14,437

Hi anonimnystefy and bobbym,

Find the sum of the following Arithmetic Progressions:

#4468. 2, 7, 12, ..., to 10 terms.

#4469. -37, -33, -29, ....., to 12 terms.

Character is who you are when no one is looking.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 86,636

Hi ganesh;

**In mathematics, you don't understand things. You just get used to them.Of course that result can be rigorously obtained, but who cares?Combinatorics is Algebra and Algebra is Combinatorics.**

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**John E. Franklin****Member**- Registered: 2005-08-29
- Posts: 3,562

#4468.)

**igloo** **myrtilles** **fourmis**

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**ganesh****Moderator**- Registered: 2005-06-28
- Posts: 14,437

Hi,

bobbym : The solutions #4468 and #4469 are correct. Neat work!

John E. Franklin : The solution #4468 is correct. Good work!

#4470. Find the sum : 7 + 10.5 + 14 + .... + 84.

#4471. Find the sum : 34 + 32 + 30 + ..... + 10.

Character is who you are when no one is looking.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 86,636

Hi;

**In mathematics, you don't understand things. You just get used to them.Of course that result can be rigorously obtained, but who cares?Combinatorics is Algebra and Algebra is Combinatorics.**

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**ganesh****Moderator**- Registered: 2005-06-28
- Posts: 14,437

Hi bobbym,

The solutions #4470 and #4471 are correct. Good work!

#4472. Find the sum of the Arithmetic Progression : -5 + (-8) + (-11) + ,,,,, + (-230).

#4473. In an Arithmetic Progression, given a = 5, d = 3, a[sub]n[/sub] = 50, find n and S[sub]n[/sub].

Character is who you are when no one is looking.

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**John E. Franklin****Member**- Registered: 2005-08-29
- Posts: 3,562

4472.)

**igloo** **myrtilles** **fourmis**

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 86,636

Hi;

**In mathematics, you don't understand things. You just get used to them.Of course that result can be rigorously obtained, but who cares?Combinatorics is Algebra and Algebra is Combinatorics.**

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**ganesh****Moderator**- Registered: 2005-06-28
- Posts: 14,437

Hi,

John E. Fraklin : The solution #4472 is correct. Smart work!

bobbym : The solutions #4472 and #4473 are correct. Excellent!

#4474. In an Arithmetic Progression, given a[sub]12[/sub] = 37, d = 3, find a and S[sub]12[/sub].

#4475. In an Arithmetic Progression, given a[sub]3[/sub] = 15, S[sub]10[/sub] = 125, find d and a[sub]10[/sub].

Character is who you are when no one is looking.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 86,636

Hi;

Of course that result can be rigorously obtained, but who cares?

Combinatorics is Algebra and Algebra is Combinatorics.

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**ganesh****Moderator**- Registered: 2005-06-28
- Posts: 14,437

Hi bobbym,

The solutions #4474 and #4475 are correct. Neat work!

#4476. How many terms of the Arithmetic Progression 9, 17, 25, ..... must be taken to give a sum of 636?

#4477. The first term of an Arithmetic Progression is 5, the last term is 45 and the sum is 400. Find the number of terms and the common difference.

Character is who you are when no one is looking.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 86,636

Hi;

Of course that result can be rigorously obtained, but who cares?

Combinatorics is Algebra and Algebra is Combinatorics.

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**ganesh****Moderator**- Registered: 2005-06-28
- Posts: 14,437

Hi bobbym,

The solutions #4476 and #4477 are correct. Excellent!

#4478. Find the sum of first 22 terms of an Arithmetic Progression in which d = 7 and 22nd term is 149.

#4479. Find the sum of first 51 terms of an Arithmetic Progression whose second and third terms are 14 and 18 respectively.

Character is who you are when no one is looking.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 86,636

Hi;

Of course that result can be rigorously obtained, but who cares?

Combinatorics is Algebra and Algebra is Combinatorics.

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**ganesh****Moderator**- Registered: 2005-06-28
- Posts: 14,437

Hi bobbym,

The solution

The solution #4479 is correct. Neat work!

#4480. Find the sum of the first 40 positive integers divisible by 6.

#4481. Find the sum of the first 15 multiples of 8.

Character is who you are when no one is looking.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 86,636

Hi;

Of course that result can be rigorously obtained, but who cares?

Combinatorics is Algebra and Algebra is Combinatorics.

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**ganesh****Moderator**- Registered: 2005-06-28
- Posts: 14,437

Hi bobbym,

The solutions #4480 and #4481 are perfect. Stupendous!

#4482. Find the sum of all the two-digit natural numbers which are divisible by 4.

#4483. Find the sum of all natural numbers between 100 and 200 which are divisible by 4.

Character is who you are when no one is looking.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 86,636

Hi;

Of course that result can be rigorously obtained, but who cares?

Combinatorics is Algebra and Algebra is Combinatorics.

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**ganesh****Moderator**- Registered: 2005-06-28
- Posts: 14,437

Hi bobbym,

The solutions #4482 and #4483 are correct. Excellent!

#4484. Find the sum of all the natural numbers less than 100 which are divisible by 6.

#4485. Find the sum of all natural numbers between 100 and 500 which are divisible by 8.

Character is who you are when no one is looking.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 86,636

Hi;

Of course that result can be rigorously obtained, but who cares?

Combinatorics is Algebra and Algebra is Combinatorics.

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**ganesh****Moderator**- Registered: 2005-06-28
- Posts: 14,437

Hi bobbym,

The solutions #4484 and #4485 are correct. Good work!

#4486. Find the number of terms of the Arithmetic Progression 54, 51, 48, .... so that their sum is 513.

#4487. If the nth term of an Arithmetic Progression is (2n + 1), find the sum of first n terms of the Arithmetic Progression.

Character is who you are when no one is looking.

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**mathaholic****Member**- From: Juliania
- Registered: 2012-11-29
- Posts: 2,845
- Website

I Don't Know 4487.

"Double the fun, double the thrill, double the coolness" - Julianthewiki

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 86,636

Hi ganesh;

Of course that result can be rigorously obtained, but who cares?

Combinatorics is Algebra and Algebra is Combinatorics.

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**ganesh****Moderator**- Registered: 2005-06-28
- Posts: 14,437

Hi julianthemath and bobbym,

The solution #4486 is correct; Excellent, julianthemath!

The solutions #4486 and #4487 are correct; Brilliant, bobbym!

The solution #4487

, julianthemath!#4488. The sum of the third and the seventh terms of an Arithmetic Progression is 6 and their product is 8. Find the sum of first sixteen terms of the Arithmetic Progression.

#4489. Which term of the Arithmetic Progression : 121, 117, 113, ...... , is the first negative term?

Character is who you are when no one is looking.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 86,636

Hi ganesh;

Of course that result can be rigorously obtained, but who cares?

Combinatorics is Algebra and Algebra is Combinatorics.

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