What is the sum of the arithmetic sequence 140, 134, 128..., if there are 33 terms?

Question

What is the sum of the arithmetic sequence 140, 134, 128..., if there are 33 terms?
Choose one answer.
A. 1,364
B. 1,408
C. 1,452
D. 1,496

Answer 1

a1 = 140, d=-6, n=33

a33 = 140 -6(32) = - 52 = 33rd or last term

s33 = 33(140-52)/2 = 33(88/2) = 33(44)= 1,452

C is correct