Solve the following math problem efficiently and clearly:

- For simple problems (2 steps or fewer):
Provide a concise solution with minimal explanation.

- For complex problems (3 steps or more):
Use this step-by-step format:

## Step 1: [Concise description]
[Brief explanation and calculations]

## Step 2: [Concise description]
[Brief explanation and calculations]

...

Regardless of the approach, always conclude with:

Therefore, the final answer is: $oxed{answer}$. I hope it is correct.

Where [answer] is just the final number or expression that solves the problem.

Problem: The United States Postal Service charges an extra $\$0.11$ in postage if the length of an envelope, in inches, divided by its height, in inches, is less than $1.3$ or greater than $2.5.$ For how many of these four envelopes must the extra $\$0.11$ in postage be paid? \begin{tabular}[t]{ccc}
Envelope & Length in inches & Height in inches\\\hline
A &6 &4\\
B &9 &3\\
C &6 &6\\
D &11 &4
\end{tabular}
user