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

Question

Quizplus · Accepted Answer

To solve this problem, we will use the binomial probability formula:

P(X=k) = (n choose k) * p^k * (1-p)^(n-k)

Where:
- X is the number of blue parakeets the store gets (in this case, we want X=1)
- n is the total number of parakeets the supplier selects to send to the store (in this case, n=3)
- k is the number of blue parakeets the supplier selects to send to the store (in this case, k=1)
- p is the probability of selecting a blue parakeet (in this case, p=0.1)

Plugging in the numbers, we get:

P(X=1) = (3 choose 1) * 0.1^1 * 0.9^2
P(X=1) = 3 * 0.1 * 0.81
P(X=1) = 0.243

So the chance that the pet store gets exactly one blue parakeet is 0.243, which corresponds to choice B.

A Pet Supplier Has a Stock of Parakeets of Which