Question

An arithmetic sequence is given by the formula Ln= 42+11n.

Answer 1

First term = 42 + 11 x 1 = 53
Last term = 42 + 11 x 2000 = 22042
Sum of 2000 terms = (2000/2)(53 + 22042) = 1000 x 22095 = 22 095 000