The problem presented in the image asks to "trouver le nombre qui complète logiquement la série" (find the number that logically completes the series) with the sequence:

$3, 8, 13, 18, 23, ?$

This is an arithmetic sequence, where each number increases by 5.

• $8 - 3 = 5$
• $13 - 8 = 5$
• $18 - 13 = 5$
• $23 - 18 = 5$

Following the same pattern, the next number would be:

$23 + 5 = 28$

So, the correct number to complete the sequence is 28.

Would you like more details on arithmetic sequences or to explore related concepts?

Here are 5 questions to expand on this:

1. What is the general formula for an arithmetic sequence?
2. How do you find the common difference in a sequence?
3. What other types of sequences (e.g., geometric) can be used in problems like this?
4. How can arithmetic sequences be applied in real-world scenarios?
5. Can arithmetic sequences ever be decreasing?

Tip: In arithmetic sequences, the common difference between consecutive terms is always constant.