.1.In a large bag of marbles, 25% of them are red. A child chooses 4 marbles from this bag. If the child chooses the marbles at random, what is the chance that the child gets exactly three red marbles? . A) 0.047. B) 0.141 . C) 0.211 . D) 0.063. . 2.A pet supplier has a stock of parakeets of which 10% are blue parakeets. A pet store orders 3 parakeets from this supplier. If the supplier selects the parakeets at random, what is the chance that the pet store gets exactly one blue parakeet?. A) 0.081 . B) 0.243 . C) 0.027 . D) 0.003 . In a large bag of marbles, 25% of them are red. A child chooses 4 marbles
Answer:
A: 0.047
B: 0.243
Step-by-step explanation:
A:
\(\frac{4!}{3!(4-3)!} (0.25)^{3} (1-0.25)^{4-3}\)
= 0.0468 ≈ 0.047
B:
The probability of a blue parakeet to be chosen is 0.10 and the probability of a non blue parakeet is 0.90.
We can conclude from the given situation, the following combinations:
No blue parakeet: \(0.90^{3}= 0.729\)
If 1 blue parakeet is selected: \(0.90^{2}\times0.10= 0.081\)
When there are 2 blue parakeets: \(0.90\times0.10^{2} =0.009\)
When 3 blue parakeets: \(0.10^{3} =0.001\)
So,the chance that the pet store gets exactly one blue parakeet is given by:
\(0.081\times3 =0.243\)