Arithmetic Series $S_n=\frac{n}{2}[2a+(n-1)d]$ or $S_n=\frac{n}{2}(a+t_n)$

  1. 1
    Find the sum of the first 40 terms given the arithmetic series:
    $$2+5+8+11+...$$
  2. 2
    Find the sum of the first 25 terms given the arithmetic series:
    $$-3 -7 -11 -15-...$$
  3. 3
    Find $S_{30}$ given the arithmetic series:
    $$24+19+14+9+...$$
  4. 4
    Find the sum given the arithmetic series:
    $$3+5+7+9+...+71$$
  5. 5
    Find the sum given the arithmetic series:
    $$25+18+11+4+...-59$$
  6. 6
    Find the sum given the arithmetic series:
    $$4+7+10+13+...+127$$
  7. 7
    A theatre has 18 seats in the front row and 3 additional seats in each following row.

    How many seats are there if the theatre has 20 rows?
  8. 8
    A log pile has 26 logs on the bottom row. each row above has one less log to form a triangular pile with 1 log at the top.

    How many logs are there in the pile?
  9. 9
    Find the first four terms of the arithmetic series with:
    $$t_{12}=35\; \quad S_{20}=610$$
    Good test question!
  10. 10
    Find the first four terms of the arithmetic series with:
    $$t_{5}=14\; \quad S_{10}=165$$
  11. 11
    The sum of the first four terms of an arithmetic sequence is $50$ and $S_{6}=93$. find the first three terms.$$ $$ Good test question!

$$e=mc^2$$