Problem 30 - College Algebra

Question

Use the Fundamental Counting Principle to solve A popular brand of pen is available in three colors (red, green, or blue) and four writing tips (bold, medium, fine, or micro). How many different choices of pens do you have with this brand?

Step-by-Step Solution

Answer

You have 12 different choices of pens with this brand.

Step 1: Identify the number of outcomes for each event

There are three colors to pick from: red, green and blue. And there are four writing tips to choose: bold, medium, fine, or micro. So there are 3 outcomes for color and 4 outcomes for writing tips.

Step 2: Apply the Fundamental Counting Principle

According to the Fundamental Counting Principle, the total number of outcomes is the product of the number of outcomes for each event. Here, the total number of pen choices is found by multiplying the outcomes for color and writing tips.

Step 3: Calculation

The total number of pen choices equals the number of color options multiplied by the number of writing tip options, so the number of pen choices is \( 3 \times 4 = 12 \).

Key Concepts

Combinatorics

Combinatorics is a branch of mathematics that deals with counting, arranging, and analyzing possible outcomes or combinations in a systematic way. This field is incredibly helpful in solving problems where you need to determine the total number of possible configurations, like the pen exercise we are discussing. Combinatorics encompasses various methods, including permutations, combinations, and the Fundamental Counting Principle.

• Permutations consider scenarios where order matters, such as ranking items.
• Combinations focus on selecting items where order does not matter.

In the pen exercise, we aren't concerned with the order of selection, but rather the total number of possibilities when choosing colors and writing tips. That's where the Fundamental Counting Principle comes into play. Understanding the basics of combinatorics provides a foundation to solve many real-life counting problems efficiently.

Multiplication Principle

The Multiplication Principle, also known as the Fundamental Counting Principle, is a core concept in combinatorics. It helps determine the total number of outcomes when you have two or more choices to make independently. Essentially, if you can choose one event in 'm' ways and a second event in 'n' ways, the total number of ways to choose both is given by multiplying these numbers, i.e., \( m \times n \). In our example with the pens:

• The number of color choices (red, green, blue) provides us with 3 outcomes.
• Each color choice can be paired with any of the 4 writing tips (bold, medium, fine, micro), another set of 4 outcomes.

Applying the Multiplication Principle, you multiply 3 outcomes of colors by 4 outcomes of tips to get the total number of pen choices: \( 3 \times 4 = 12 \). This principle gives you a straightforward method to calculate combinations of independent events.

Outcomes

The concept of outcomes is fundamental in probability and combinatorics, where it refers to the possible results that can occur from a specific action or series of actions. In counting problems, identifying the distinct outcomes is crucial for applying principles like the Fundamental Counting Principle correctly. For the pen exercise:

• The first set of outcomes comes from the color options: red, green, or blue.
• The second set of outcomes is from the writing tip options: bold, medium, fine, or micro.

Each possible combination of color and writing tip creates a unique outcome. By identifying that there are 3 color outcomes and 4 tip outcomes, we logically combined them to discover there are 12 unique pen outcomes. Recognizing each distinct outcome allows you to systematically approach various counting and probability problems efficiently. Understanding how outcomes work will assist in breaking down more complex scenarios down the road.