When solving word problems about sequences and series, I’ve found some helpful strategies. Here’s how I do it:

1. Understand the Problem: First, I read the problem carefully. I highlight important information and figure out what the question is asking.

2. Identify the Sequence Type: Next, I check if it's an arithmetic sequence, a geometric sequence, or something else. For example, if the problem talks about a constant difference, it’s probably arithmetic. If it mentions a constant ratio, it’s likely geometric.

3. Write the General Formula: After I know the type, I write down the general formulas.

   • For an arithmetic sequence, the formula for the $n$-th term is:
     $a_n = a_1 + (n-1)d$
     Here, $d$ is the common difference.

   • For a geometric sequence, I use:
     $a_n = a_1 \cdot r^{(n-1)}$
     In this case, $r$ is the common ratio.

4. Substitute Values: Then, I replace the known values from the problem into these formulas.

5. Solve and Check: Finally, I find the answer to the question and double-check to make sure it makes sense.

These steps help make dealing with sequences and series a lot easier!