Ask Question
28 November, 11:42

What is the sum of the first 35 terms in the series 7 + 9 + 11 + ... ?

a.

29

c.

1645

b.

1399

d.

1435

+2
Answers (1)
  1. 28 November, 12:09
    0
    If a sequence is arithmetic or geometric there are formulas to find the sum of the first nn terms, denoted Sn, without actually adding all of the terms.

    (Note that a sequence can be neither arithmetic nor geometric, in which case you'll need to add using brute force, or some other strategy.)

    To find the sum of the first nn terms of an arithmetic sequence use the formula, Sn=[n (a1+an) ]/2

    where n is the number of terms, a1 is the first term and an is the last term.

    First find the 35 th term:

    a35=a1 + (n-1) (d) = 7 + (34) (2) = 75

    Then find the sum:

    Sn=[n (a1+an) ]/2 = [35 (7+75) ]/2 = 1435

    Thus, the answer is:

    d.

    1435
Know the Answer?
Not Sure About the Answer?
Find an answer to your question 👍 “What is the sum of the first 35 terms in the series 7 + 9 + 11 + ... ? a. 29 c. 1645 b. 1399 d. 1435 ...” in 📗 Mathematics if the answers seem to be not correct or there’s no answer. Try a smart search to find answers to similar questions.
Search for Other Answers