Which sequence consists of four consecutive natural numbers?

Concept

Consecutive natural numbers are counting numbers that differ by 1 when arranged in increasing order.

For a sequence a, b, c, d to be consecutive, the three differences b − a, c − b, and d − c must each equal 1.

Application

1. For 3, 4, 5, 6: 4 − 3 = 1, 5 − 4 = 1, and 6 − 5 = 1.

2. All adjacent differences are 1, so the numbers form one uninterrupted counting sequence.

Cross-check and contrast

Computing the adjacent differences for every sequence gives:

• 5, 7, 9, 11: each adjacent difference is 2.

• 2, 4, 6, 8: each adjacent difference is 2.

• 3, 4, 5, 6: each adjacent difference is 1.

• 1, 3, 5, 7: each adjacent difference is 2.

Result

Therefore, the required sequence is 3, 4, 5, 6.