# Thread: arithmetic progression--need help

1. ## arithmetic progression--need help

Consider the sum of the first n integers. For what value of n will the sum first exceed 1000?

need help

2. Originally Posted by nikk
Consider the sum of the first n integers. For what value of n will the sum first exceed 1000?

need help
hint: the sum of the first n positive integers is given by $\frac {n(n + 1)}2$

3. Originally Posted by nikk
Consider the sum of the first n integers. For what value of n will the sum first exceed 1000?

need help
Solve $\sum_{k=1}^{n}k=\frac{n(n+1)}{2}\geqslant 1000$

4. is it the formula both of you come from this

Sum(n) = 1+2+3+4 ....... +n = n(n+1)/2

???

5. my ans is = 45

can u reconfirm it??

6. The formula for summing integers from 1 to n is $\frac{n(n+1)}{2}$. That should get you started.

edit: How did I miss all those posts?

Yes OP the answer is 45

7. Originally Posted by Jameson
The formula for summing integers from 1 to n is $\frac{n(n+1)}{2}$. That should get you started.

edit: How did I miss all those posts?

Yes OP the answer is 45
tq for your time

8. Originally Posted by nikk
tq for your time
in regards to the title of this post, note that you could have derived this formula by the formula for the sum of the first n terms of an arithmetic sequence.