Verified answer

Answer:

To find the sum of the first 20 terms of the arithmetic series 2, 7, 12, ..., we can use the formula:

S_n = n/2 * [2a + (n-1)d]

where S_n is the sum of the first n terms of the series, a is the first term, d is the common difference, and n is the number of terms.

In this case, a = 2, d = 5 (since each term is 5 more than the previous term), and n = 20. Substituting these values into the formula, we get:

S_20 = 20/2 * [2(2) + (20-1)(5)]

= 10 * [4 + 95]

= 10 * 99

= 990

Therefore, the sum of the first 20 terms of the arithmetic series 2, 7, 12, ... is 990.