Well as this formula is valid only for natural numbers so the sum will also be a natural number.
If it is not specified natural number or k is a rational number with denominator \(\ne\) 1 then the answer is \(\infty\)

@Sravanth Chebrolu Do (0,7) and (7,0) not lie in any quadrant? Coz the definition of the point in the 1st quadrant is x,y>0. Anyways.. If included, they should be 8 in number , eh. I think there is a typo.

Well , I think any class 10 student has the ability to count the number of solutions manually , it's just that the method of Generating Functions works for finding solutions of the type :\(x+y = N\) or other types .

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TopNewestThe formula for the number of Natural numbers satisfying \(x + y = k\) is always \(k-1\).

So in this case

k = 7. Hence number of points are6This formula is just a observation based. Please verify it @Azhaghu Roopesh M @Krishna Ar @Sravanth Chebrolu

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Yes, I too think the same, but if the no. of points asked is in fractions or decimals there can be many . . .

What do you say @Rajdeep Dhingra ???

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Comment deleted Mar 25, 2015

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Well as this formula is valid only for natural numbers so the sum will also be a natural number.

If it is not specified natural number or

kis a rational number with denominator \(\ne\) 1 then the answer is \(\infty\)Log in to reply

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If the number of points(x,y) are said to be only whole numbers(not decimals), then there are 6, they are:

\( (1,6),(2,5),(3,4),(4,3),(5,2) and (6,2) \)

If it is mentioned, including decimals, then it is infinite . . .

What do you say Azhaghu Roopesh M ???

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@Sravanth Chebrolu Do (0,7) and (7,0) not lie in any quadrant? Coz the definition of the point in the 1st quadrant is x,y>0. Anyways.. If included, they should be 8 in number , eh. I think there is a typo.

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Yeah it was a typo, I've changed it. And yes, I think what you said is also right, the points (7,0) and (0,7) lie on the

axesnot thequadrants.Log in to reply

Yeah , since the number 7 is quite small , we can count it out .

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Exactly. Is there any formula for these kind of problems???

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I guess there would have been more information provided. Most likely the question would have specified \(x,y\) to be integers.

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But it has been said that x,y belong to the first quadrant , so automatically \(x,y \geq 0\)

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Is this the exact same question ? If so , it is a simple question of Generating Functions

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Generating functions? Are you sure? This is a JSTSE question, so its for classes 10 or below I think.

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Well , I think any class 10 student has the ability to count the number of solutions manually , it's just that the method of Generating Functions works for finding solutions of the type :\(x+y = N\) or other types .

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Not exactly below.. The maths questions were mainly Of class 10 level iincluding all AP, GP , Quadratics, Vieta's etc...

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