Question

5,18, 31, 44, 57, 70
Which expression represent the nth number in this sequence?

Answer 1

a(n) = 5 + 13(n - 1)

Explanation:

Note that each new number is obtained by adding 13 to the previous number. The common difference is 13 and the first number is 5. The general formula for an arithmetic sequence is

a(n) = a(1) + d(n - 1), where d is the common difference.

Here,

a(n) = 5 + 13(n - 1)