Question

Please help!!! I still have about 8 more to do ;;

Answer 1

You can just manually add 6 until you come across 324.  So the answer is 12 terms.

You can also use this formula:

Sum = n/2 * (2a + (n-1)d)

and solve for n.

(n = number of terms, a = starting term, d = common difference)