For an arithmetical sequence, the first term is 2 and the common difference is 3. Find the sum of the first 11 terms
Answer Details
An arithmetic sequence is a sequence of numbers where the difference between any two consecutive terms is constant. In this case, the first term is 2 and the common difference is 3, so the sequence is:
2, 5, 8, 11, 14, 17, 20, 23, 26, 29, 32
To find the sum of the first 11 terms of this sequence, we can use the formula for the sum of an arithmetic series:
Sn = n/2 * (a1 + an)
where Sn is the sum of the first n terms, a1 is the first term, and an is the nth term.
In this case, n = 11, a1 = 2, and an = 32 (the 11th term can be found by adding the common difference 3, 10 times to the first term 2).
So, substituting the values in the formula:
Sn = 11/2 * (2 + 32)
Sn = 11/2 * 34
Sn = 187
Therefore, the sum of the first 11 terms is 187. So the correct answer is.