Question
Two balls are taken at the same time from a bag containing three black, three yellow and three red balls. (i) Find the probability that both balls are red. (i)
Ask by Hanson Schmidt. in Ireland
Jan 24,2025
Real Tutor Solution
Tutor-Verified Answer
Answer
The probability that both balls are red is \(\frac{1}{12}\).
Solution
To find the probability that both balls drawn are red, we'll follow these steps:
### **Given:**
- Total balls in the bag:
- Black balls = 3
- Yellow balls = 3
- Red balls = 3
- Total number of balls = 3 + 3 + 3 = **9**
### **Step 1: Calculate the Total Number of Ways to Choose 2 Balls**
The total number of ways to choose 2 balls out of 9 is given by the combination formula:
\[
\text{Total combinations} = C(9, 2) = \frac{9!}{2!(9-2)!} = \frac{9 \times 8}{2 \times 1} = 36
\]
### **Step 2: Calculate the Number of Favorable Ways (Both Balls are Red)**
There are 3 red balls. The number of ways to choose 2 red balls out of these 3 is:
\[
\text{Red combinations} = C(3, 2) = \frac{3!}{2!(3-2)!} = \frac{3 \times 2}{2 \times 1} = 3
\]
### **Step 3: Calculate the Probability**
The probability \( P \) that both balls drawn are red is the ratio of the favorable combinations to the total combinations:
\[
P(\text{both red}) = \frac{\text{Red combinations}}{\text{Total combinations}} = \frac{3}{36} = \frac{1}{12}
\]
### **Final Answer:**
The probability that both balls are red is \(\frac{1}{12}\).
Reviewed and approved by the UpStudy tutoring team
Like
error msg
Explain
Simplify this solution
Beyond the Answer
To find the probability that both balls drawn are red, first calculate the total number of ways to select 2 balls from the 9 balls available (3 black, 3 yellow, and 3 red). This is given by the combination formula C(n, k) = n! / (k!(n-k)!), so C(9, 2) = 36. Next, compute the number of ways to choose 2 red balls from the 3 available, which is C(3, 2) = 3. Now, the probability is the number of successful outcomes divided by the total number of outcomes: P(both red) = Number of ways to choose 2 red / Total ways to choose 2 = 3 / 36 = 1/12. The final answer is: Probability = 1/12.