Question

The first three terms of a sequence are given. Round to the nearest thousandth (if

necessary).
261, 256, 251, ...
Find the 46th term.

Answer 1

The 49th term is 39.

Explanation:

This is a decreasing arithmetic sequence. We recognize this because the difference from one term to the next is 5.

The general formula needed here is a(n) = a(1) - 5(n - 1)

a(45) = 261 - 5(46 - 1), or

a(45) = 261 - 225 = 39

The 49th term is 39.