What is the sum of integers from 1 to n with r = 1 if n = 20?

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The discussion revolves around calculating the sum of integers from 1 to n, specifically when n equals 20 and r equals 1. The correct formula for this sum is n(n+1)/2, leading to a total of 210 for n = 20. Participants express confusion regarding the role of r in the equation, with some interpreting it as a variable in a diophantine equation. The only solution derived from this interpretation is n = 3, m = 4, and r = 2, though there is uncertainty about the problem's original intent. Overall, the main focus is on clarifying the sum of integers and the relevance of r in the context of the problem.
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sum of 1 n = 20/ r = 1
r(r+1)
 
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tharindhudg said:
sum of 1 n = 20/ r = 1
r(r+1)

It would help if you could clarify your expression.
 
tharindhudg said:
sum of 1 n = 20/ r = 1
r(r+1)

If construed as a number theory problem, the best that I could come up with

sum of 1 to n = r(r+1) sum of 1 to 3 = 2*3 etc.
sum of 1 to n = 20/r sum of 1 to 4 = 20/2
So r = 2
 
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If I understand you correctly, you are summing the integers from 1 to n.
This sum is n(n+1)/2. I have no idea what you mean by r.
 
This topic made me laugh for some reason.
 
mathman said:
If I understand you correctly, you are summing the integers from 1 to n.
This sum is n(n+1)/2. I have no idea what you mean by r.

I viewed it as two diophantine equations in two variables

n(n+2)/2 = r(r+1) and m(m+1)/2 = 20/r for which the only solution is n = 3, m =4, r = 2

I did not use the formula n(n+1)/2 since I knew the values of n(3) and n(4) already.

No certainty that I understood the problem correctly though I don't see how there could be a different problem intended.
 

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