Question**: A bag contains 5 red, 4 blue, and 6 green marbles. What is the probability of drawing a blue marble? - Protocolbuilders
Probability of Drawing a Blue Marble: A Simple Guide with Marbles
Probability of Drawing a Blue Marble: A Simple Guide with Marbles
If you’ve ever wondered about the chance of pulling a blue marble from a bag full of different colored marbles, you’re in the right place! In this article, we’ll explore a classic probability question using a real-world example: a bag containing 5 red, 4 blue, and 6 green marbles. We’ll break down how to calculate the probability of drawing a blue marble, explain the basic principles of probability, and show why this concept applies widely in statistics and everyday decision-making.
Understanding the Context
Understanding the Problem
You’re given a bag with:
- 5 red marbles
- 4 blue marbles
- 6 green marbles
Total number of marbles:
5 + 4 + 6 = 15 marbles
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Key Insights
The question asks: What is the probability of drawing a blue marble?
Probability measures how likely an event is to occur. In probability terms, it’s calculated as:
\[
\ ext{Probability} = \frac{\ ext{Number of favorable outcomes}}{\ ext{Total number of possible outcomes}}
\]
Here, the favorable outcome is drawing a blue marble — there are 4 of those.
Final Thoughts
Step-by-Step Calculation
- Identify favorable outcomes: 4 blue marbles
2. Identify total possible outcomes: 15 marbles in total
So, the probability \( P \) of drawing a blue marble is:
\[
P(\ ext{blue}) = \frac{4}{15}
\]
This fraction is already in simplest form, so the probability is approximately 0.267 or 26.7%.
Why This Matters: Probability Fundamentals
This simple problem illustrates key ideas in probability theory:
- Sample space: The complete set of outcomes — here, 15 marbles.
- Event: A specific outcome or set of outcomes — here, drawing a blue marble.
- Uniform probability assumption: Assuming marbles are evenly placed and no marble is favored, each has an equal chance.
Understanding these concepts helps in making informed guesses in games of chance, scientific experiments, risk analysis, and daily choices involving uncertainty.