Which of the following statements correctly describes the sequence 3, 8, 13, 18, . . .?

Statement #1: It is an arithmetic sequence.

Statement #2: It is a geometric sequence

1 answer

To analyze the sequence 3, 8, 13, 18, ... we need to look at the differences between consecutive terms to determine whether it is arithmetic or geometric.

  1. Arithmetic Sequence: In an arithmetic sequence, the difference between consecutive terms is constant. Let's calculate the differences:
  • 8 - 3 = 5
  • 13 - 8 = 5
  • 18 - 13 = 5

The difference is constant (5) between consecutive terms, which means this sequence is indeed an arithmetic sequence.

  1. Geometric Sequence: In a geometric sequence, the ratio of consecutive terms is constant. Let's check the ratios:
  • 8 / 3 ≈ 2.67
  • 13 / 8 = 1.625
  • 18 / 13 ≈ 1.385

The ratios are not constant, which means this sequence is not a geometric sequence.

Based on this analysis:

  • Statement #1: It is an arithmetic sequence. (True)
  • Statement #2: It is a geometric sequence. (False)

Thus, the correct description is that the sequence is an arithmetic sequence.