For a certain sequence the sums of the first five and six terms are and respectively

MATHEMATICS · Single correct · A Level · Mathematics · Sequences and series · Sequences and series

Problem

For a certain sequence the sums of the first five and six terms are

S_5 = 40

and

S_6 = 54

respectively. Find the sixth term

a_6

. (a)

12

(b)

9

(c)

14

(d)

15