Question: What is the sum of the first n terms of the arithmetic series 2, 5, 8, ...?
Options:
Correct Answer: n/2 * (2 + (n-1) * 3)
Solution:
The first term a = 2, common difference d = 3. The sum of the first n terms S_n = n/2 * (2a + (n-1)d) = n/2 * (2 + (n-1) * 3).