Answer: Our required probability is 0.3387.
Step-by-step explanation:
Since we have given that
Number of red cards = 4
Number of black cards = 5
Number of cards drawn = 5
We need to find the probability of getting exactly three black cards.
Probability of getting a black card = ![\dfrac{5}{9}](https://tex.z-dn.net/?f=%5Cdfrac%7B5%7D%7B9%7D)
Probability of getting a red card = ![\dfrac{4}{9}](https://tex.z-dn.net/?f=%5Cdfrac%7B4%7D%7B9%7D)
So, using "Binomial distribution", let X be the number of black cards:
![P(X=3)=^5C_3(\dfrac{5}{9})^3(\dfrac{4}{9})^2\\\\P(X=3)=0.3387](https://tex.z-dn.net/?f=P%28X%3D3%29%3D%5E5C_3%28%5Cdfrac%7B5%7D%7B9%7D%29%5E3%28%5Cdfrac%7B4%7D%7B9%7D%29%5E2%5C%5C%5C%5CP%28X%3D3%29%3D0.3387)
Hence, our required probability is 0.3387.