Maximizing Notebooks and Pencils under Budget

Maria is preparing for a math competition and decides to practice solving various types of word problems. One particular problem states that she needs to buy notebooks and pencils for her study group. Each notebook costs $3, and each pencil costs $1. If Maria has a budget of $30 and she wants to buy twice as many notebooks as pencils, how many notebooks and pencils can she buy?

Let the number of pencils be represented as $p$ and the number of notebooks as $n$. Based on the problem, we can formulate the following equations:

1. Budget constraint: $3n + p \leq 30$

2. Notebooks to pencils: $n = 2p$

Determine the maximum number of notebooks and pencils Maria can buy while adhering to her constraints.