SOLUTION: The instructor in a humanities class says that students have a 15% probability of making an A in her class, 20% probability of making a B, 25% chance of making a C, 20% of making a

Question 507249: The instructor in a humanities class says that students have a 15% probability of making an A in her class, 20% probability of making a B, 25% chance of making a C, 20% of making a D, and 5% of making a F. The possible grades are A,B,C,D,F and N. What is the probability that a randomly selected student will make a passing grade, that is an A,B, or C?
A. 30%
B. 33%
C. 50%
D Cannot be determined from the information given.
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
The instructor in a humanities class says that students have a 15% probability of making an A in her class, 20% probability of making a B, 25% chance of making a C, 20% of making a D, and 5% of making a F. The possible grades are A,B,C,D,F and N. What is the probability that a randomly selected student will make a passing grade, that is an A,B, or C?
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P(A or B or C) = 0.15+0.20+0.25 = 0.60
Note: Only 80% of the students are accounted for so
I guess they want you to choose "D" as an answer.
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Cheers,
Stan H.
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A. 30%
B. 33%
C. 50%
D Cannot be determined from the information given.

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