Question

The first ten terms of a sequence are

1, 2, 6, 1, 2, 6, 1, 2, 6, 1...
with the pattern visible above repeating indefinitely.

(a) Find 20.
(b) Find u50.
(c) Find the sum of the first 30 terms.
(d) Find the sum of the first 31 terms.
(e) Given that the sum of the first N terms is 84, find N.

Answer 1

(a) The 20th term of the sequence is 1.

(b) The 50th term of the sequence is 6.

(c) The sum of the first 30 terms of the sequence is 20.

(d) The sum of the first 31 terms of the sequence is 21.

(e) Given that the sum of the first N terms is 84, N is 28.