Question

Select the correct answer.

What is the sum of the first 30 terms of this arithmetic sequence?
6, 13, 20, 27, 34, ...
OA 3,225
OB. 3,255
OC. 3,325
OD. 3,525

Answer 1

the answer is A. 3225

Explanation:

S₃₀ = 30/2 [ 2 x 6 + (30 - 1) x 7 ]

15 [ 12 + 29 x 7 ]

15 [ 12 + 203 ]

15 x 215

=3225