Answer:
B
Step-by-step explanation:
because it is
Given:
μ = 500 days, the population mean
σ = 60 days, the population standard deviation
Therefore
μ + σ = 560
μ - σ = 440
μ + 2σ = 620
μ - 2σ = 380
μ + 3σ = 680
μ - 3σ = 320
The figure shown below illustrates the normal distribution
About 68% of the total area lies in x = (μ-σ, μ+σ)
About 95% of the total area lies in x = (μ-2σ, μ+2σ)
About 99.7% of the total area lies in x = (μ-3σ, μ+3σ).
<span>The number 8.5 is being added. </span>
2560000 sequences of answers are possible.
<em><u>Explanation</u></em>
Total number of questions = 10
First 4 questions have 5 choices each and remaining (10-4)= 6 questions have 4 choices each.
So, the possible sequences of answers for first 4 questions 
and the possible sequences of answers for remaining 6 questions 
Thus, the total possible number of sequences of answers = (625 × 4096) = 2560000