The problem in the image asks to find the value of $n$ for the arithmetic sequence 13, 15, 17, ..., 69.

This sequence is an arithmetic progression (AP), where:

• The first term ($a$) = 13
• The common difference ($d$) = 15 - 13 = 2
• The last term = 69

The formula for the $n$-th term of an arithmetic progression is given by: $a_n = a + (n - 1) \cdot d$ Substituting the known values: $69 = 13 + (n - 1) \cdot 2$ Now, solve for $n$: $69 - 13 = (n - 1) \cdot 2$ $56 = (n - 1) \cdot 2$ $n - 1 = \frac{56}{2} = 28$ $n = 28 + 1 = 29$

Thus, the value of $n$ is 29. The correct answer is b. 29.

Would you like more details or have any questions?

Here are 5 related questions:

1. How do you find the common difference in an arithmetic sequence?
2. What is the general formula for the $n$-th term in any arithmetic sequence?
3. How can you find the sum of an arithmetic sequence?
4. What is the difference between arithmetic and geometric sequences?
5. How can we derive the formula for an arithmetic progression?

Tip: Always check if the sequence is arithmetic by verifying the common difference between consecutive terms.