The answer is 2.25 hours, or 2 hours and 25 minutes.
9.50-5=4.50
4.50/2=2.25
The probability that students who were randomly selected studied for the test, if they pass it with a B or higher grade is: D. 0.80.
<h3>How to calculate the probability?</h3>
In this exercise, you're required to determine the probability that students who were randomly selected studied for the test, if they pass it with a B or higher grade. Thus, we would apply Bayes's theorem.
- Let S represent studied for.
- Let B represent a score of B or higher grade
Therefore, we need to find P(S|B):

S|B = 0.80.
Read more on probability here: brainly.com/question/25870256
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<u>Complete Question:</u>
At the beginning of the semester, a professor tells students that if they study for the tests, then there is a 55% chance they will get a B or higher on the tests. If they do not study, there is a 20% chance that they will get a B or higher on the tests. The professor knows from prior surveys that 60% of students study for the tests. The probabilities are displayed in the tree diagram.
Question 1 = 8 x 7.2 x 3
= (use calculator)
Q2 = 10 x 12
= ? X 14
= use calculator
Then half it because it’s a triangle
Answer:
he kind of cultural value portrayed in melody would be ( B ) reservation
Explanation: