Laura opened a deposit account. IFor the arithmetic sequence beginning with the terms {-2, 0, 2, 4, 6, 8...}, what is the sum of the first 18 terms? 238 270 304 340n the first month, she made an initial deposit of $2500. Starting in month two, she plans to contribute $225 each month. The account does not pay any interest. After how many months will she have a total of $6,775? 21 months 18 months 20 months 15 months