Posted by **Crystal** on Saturday, January 12, 2013 at 2:53pm.

Okay, so I know this should be really easy but my mind is just drawing a blank:

For each series, calculate t12 and S12

a) 37 + 41 + 45 + 49 + ...

Okay so I calculated S12 to be 708, and I know that's right.

For t12, I know I can easily find the general formula and then use that to find t12, but isn't there a faster way to do it knowing that the sum is 708?

- Math -
**Crystal**, Saturday, January 12, 2013 at 3:09pm
Oh. I guess the point of the question was for you to find t12 first by using the general formula so that you could have the last term, which would allow us to use the simpler arithmetic series formula, i.e., n(t1+tn)/2 rather than n/2(2a+(n-1)d)

But I'd still like to know if there IS a way to find t12 with S12, just in case that comes up later or something.

## Answer This Question

## Related Questions

- Math - Is there a way to find the term number of a sum in an arithmetic series...
- Calculus - I'm studying infinite series and am really struggling with memorizing...
- math - t11=19 and t17=61.then what will be S12? arithmetic series question
- math please help - Point X is on line AC such that AX = 3 CX = 12. If <ABC...
- Chemistry - Okay, I feel like this question should be really easy because it's ...
- English - Hello, i'm writing an essay about how truth should be told because it ...
- college - Use the Microsoft Web site microsoft. com/ windows/ compatibility to ...
- Chemistry - An electron ps from the 6th to te 3rd energy level in the hydrogen ...
- Math - I really need help with this question please Break-even equation. Fill in...
- biology (fill in the blanks) - Big picture of natural selection/ keep in mindâ€¦ ...

More Related Questions