Calculating the Total Number of Ways to Choose Two Marbles

Oct 13, 2025 by wbrum.org 89 views

Introduction

When dealing with probability, it's essential to understand the concept of combinations and how to calculate the probability of different events occurring. In this article, we will explore the problem of choosing two marbles from a bag containing eight yellow marbles, nine green marbles, three purple marbles, and five red marbles. Our goal is to find the probability that one marble is yellow and the other marble is red.

Understanding the Problem

To solve this problem, we need to consider the total number of ways to choose two marbles from the bag and the number of ways to choose one yellow marble and one red marble. We will use the concept of combinations to calculate these values.

Calculating the Total Number of Ways to Choose Two Marbles

The total number of marbles in the bag is 8 (yellow) + 9 (green) + 3 (purple) + 5 (red) = 25 marbles. To choose two marbles from the bag, we can use the combination formula:

C(n, k) = n! / (k!(n-k)!)

where n is the total number of marbles (25) and k is the number of marbles we want to choose (2).

C(25, 2) = 25! / (2!(25-2)!) = 25! / (2!23!) = (25 × 24) / (2 × 1) = 300

So, there are 300 ways to choose two marbles from the bag.

Calculating the Number of Ways to Choose One Yellow Marble and One Red Marble

To choose one yellow marble and one red marble, we need to consider the number of ways to choose one yellow marble and the number of ways to choose one red marble. There are 8 yellow marbles and 5 red marbles, so the number of ways to choose one yellow marble is 8 and the number of ways to choose one red marble is 5.

The total number of ways to choose one yellow marble and one red marble is the product of these two values:

8 × 5 = 40

Calculating the Probability

The probability of choosing one yellow marble and one red marble is the number of ways to choose one yellow marble and one red marble divided by the total number of ways to choose two marbles:

P(YR) = 40 / 300 = 2/15

So, the probability of choosing one yellow marble and one red marble is 2/15.

Conclusion

In this article, we calculated the probability of choosing one yellow marble and one red marble from a bag containing eight yellow marbles, nine green marbles, three purple marbles, and five red marbles. We used the concept of combinations to calculate the total number of ways to choose two marbles and the number of ways to choose one yellow marble and one red marble. The probability of choosing one yellow marble and one red marble is 2/15.

Discussion

This problem can be solved using the concept of combinations and probability. The key to solving this problem is to understand the concept of combinations and how to calculate the probability of different events occurring.

Example

Suppose we have a bag containing 10 yellow marbles, 8 green marbles, 4 purple marbles, and 6 red marbles. We want to find the probability of choosing one yellow marble and one red marble. We can use the same method as before to calculate the probability:

P(YR) = (10 × 6) / C(28, 2) = 60 / 378 = 10/63

So, the probability of choosing one yellow marble and one red marble is 10/63.

Applications

This problem has many applications in real-life situations. For example, in a game of chance, the probability of choosing one yellow marble and one red marble can be used to determine the odds of winning. In a manufacturing process, the probability of choosing one yellow marble and one red marble can be used to determine the quality of the product.

References

[1] "Probability and Statistics" by Michael Sullivan
[2] "Mathematics for Dummies" by Mary Jane Sterling

Introduction

In our previous article, we explored the problem of choosing two marbles from a bag containing eight yellow marbles, nine green marbles, three purple marbles, and five red marbles. We calculated the probability of choosing one yellow marble and one red marble using the concept of combinations. In this article, we will answer some frequently asked questions related to this problem.

Q&A

Q: What is the total number of marbles in the bag?

A: The total number of marbles in the bag is 8 (yellow) + 9 (green) + 3 (purple) + 5 (red) = 25 marbles.

Q: How many ways can we choose two marbles from the bag?

A: We can use the combination formula to calculate the number of ways to choose two marbles from the bag:

C(n, k) = n! / (k!(n-k)!)

where n is the total number of marbles (25) and k is the number of marbles we want to choose (2).

C(25, 2) = 25! / (2!(25-2)!) = 25! / (2!23!) = (25 × 24) / (2 × 1) = 300

So, there are 300 ways to choose two marbles from the bag.

Q: How many ways can we choose one yellow marble and one red marble?

A: To choose one yellow marble and one red marble, we need to consider the number of ways to choose one yellow marble and the number of ways to choose one red marble. There are 8 yellow marbles and 5 red marbles, so the number of ways to choose one yellow marble is 8 and the number of ways to choose one red marble is 5.

The total number of ways to choose one yellow marble and one red marble is the product of these two values:

8 × 5 = 40

Q: What is the probability of choosing one yellow marble and one red marble?

A: The probability of choosing one yellow marble and one red marble is the number of ways to choose one yellow marble and one red marble divided by the total number of ways to choose two marbles:

P(YR) = 40 / 300 = 2/15

So, the probability of choosing one yellow marble and one red marble is 2/15.

Q: Can we use the concept of permutations to solve this problem?

A: No, we cannot use the concept of permutations to solve this problem. The concept of permutations is used to calculate the number of ways to arrange objects in a specific order, whereas the concept of combinations is used to calculate the number of ways to choose objects without regard to order.

Q: Can we use the concept of probability to solve this problem?

A: Yes, we can use the concept of probability to solve this problem. The concept of probability is used to calculate the likelihood of an event occurring, and in this case, we are calculating the probability of choosing one yellow marble and one red marble.

Q: What is the significance of the total number of marbles in the bag?

A: The total number of marbles in the bag is significant because it affects the number of ways to choose two marbles from the bag. If the total number of marbles in the bag is different, the number of ways to choose two marbles from the bag will also be different.

Q: Can we use the concept of combinations to solve other problems?

A: Yes, we can use the concept of combinations to solve other problems. The concept of combinations is a powerful tool that can be used to solve a wide range of problems, including problems involving probability, statistics, and mathematics.

Conclusion

In this article, we answered some frequently asked questions related to the problem of choosing two marbles from a bag containing eight yellow marbles, nine green marbles, three purple marbles, and five red marbles. We used the concept of combinations to calculate the number of ways to choose two marbles from the bag and the number of ways to choose one yellow marble and one red marble. We also discussed the significance of the total number of marbles in the bag and the concept of probability.