The valid probability distributions are the ones in options C and D.
<h3>
Which of the following are valid probability distributions?</h3>
For discrete random variables with probabilities p₁, p₂, ..., pₙ, there are two rules:
- All of these probabilities are numbers between 0 and 1.
- p₁ + p₂ + ... + pₙ = 1.
So, for the first rule we can discard the first option, where we have negative probabilities.
To check the other 4 options, just add the probabilities and see if the addition gives 1.
The options that add up to 1 are C and D, so these two are the correct options.
D: 1/5 + 1/10 + 1/10 + 1/10 + 1/5 + 1/10 + 1/10 + 1/10 = 1
C: 1/6 + 1/6 + 1/6 + 1/6 + 1/6 + 1/6 = 1
If you want to learn more about probability:
brainly.com/question/25870256
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A) 18
Apparently my answer has to be 20+ characters so this is filling space
Given that the score of the student on the quiz was 25c - 10(15 - c)
It can be seen that the first term of expression for her score (i.e. 25c) shows that 25 marks were awarded to each correct answer.
The second term of the expression (i.e. 10(15 - c)) represent that 10 marks were deducted from each wrong answer.
Thus, the number of wrong answers is 15 - c.
The sum of the correct answers and the wrong answers gives the total number of questions in the quiz.
Thus, the total number of questions in the quiz is given by 15 - c + c = 15.
Therefore, there are 15 questions in the quiz.
I need the whole picture that’s only half