The probability that a mature hen will lay an egg on a given day is 0.80. Hannah has 6 hens. Using the table, what is the probability that at least 2 of the hens will lay eggs on a given day?

\begin{tabular}{|c|c|c|c|c|c|c|c|}
\hline
Number of Eggs & 0 & 1 & 2 & 3 & 4 & 5 & 6 \\
\hline
Probability & 0.000064 & 0.002 & 0.015 & 0.082 & 0.246 & 0.393 & ? \\
\hline
\end{tabular}

A. 0.015

B. 0.017

C. 0.983

D. 0.998



Answer :

To determine the probability that at least 2 of Hannah's 6 hens will lay eggs on a given day, we need to follow the steps below:

1. Understand the problem:
- We are given the probabilities of 0, 1, 2, 3, 4, and 5 hens laying eggs.
- We need to find the probability of either 2, 3, 4, 5, or all 6 hens laying eggs on a given day.
- But instead of directly summing these probabilities, we can use the fact that the total probability must add up to 1.

2. Sum the probabilities for 0 and 1 hens laying eggs:
- The probability that 0 hens lay eggs, [tex]\( P(X = 0) \)[/tex], is 0.000064.
- The probability that 1 hen lays an egg, [tex]\( P(X = 1) \)[/tex], is 0.002.

3. Calculate the probability of fewer than 2 hens laying eggs:
- Add the probabilities for 0 and 1 hens laying eggs:
[tex]\[ P(X < 2) = P(X = 0) + P(X = 1) = 0.000064 + 0.002 = 0.002064 \][/tex]

4. Calculate the probability of at least 2 hens laying eggs:
- Subtract the probability of fewer than 2 hens laying eggs from 1:
[tex]\[ P(X \geq 2) = 1 - P(X < 2) = 1 - 0.002064 = 0.997936 \][/tex]

Thus, the probability that at least 2 of Hannah’s hens will lay eggs on a given day is [tex]\( \boxed{0.998} \)[/tex].