Respuesta :
Answer:
The probability of selecting two red balls is 0.132.
Step-by-step explanation:
In a bag there are 10 balls in a bag, 4 red balls and 6 black balls.
The conditions of selecting a ball are:
- If you pick one red ball, you will take it without replacement.
- If you pick one black ball, you will return it into the bag.
It is also provided that only one ball can be picked at a time.
Now, it is given that two balls are picked.
The number of ways to select a red ball in the first draw is: [tex]{4\choose 1}=4\ \text{ways}[/tex]
Compute the probability of selecting a red ball in the first draw as follows:
[tex]P(\text{First ball is Red})=\frac{{4\choose 1}}{{10\choose 1}}=\frac{4}{10}=0.40[/tex]
Now as a red ball is selected it will not be replaced.
So, there are 9 balls in the bag now.
The number of ways to select a red ball in the second draw is: [tex]{3\choose 1}=3\ \text{ways}[/tex]
Compute the probability of selecting a red ball in the second draw as follows:
[tex]P(\text{Second ball is Red})=\frac{{3\choose 1}}{{9\choose 1}}=\frac{3}{9}=0.33[/tex]
Compute the probability of selecting two red balls as follows:
[tex]P(\text{Two Red balls})=P(\text{First ball is Red})\times P(\text{Second ball is Red})[/tex]
[tex]=0.40\times 0.33\\\\=0.132[/tex]
Thus, the probability of selecting two red balls is 0.132.
