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

Algebra ->  Probability-and-statistics -> 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      Log On


   

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) About Me  (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?
---
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.
==========
Cheers,
Stan H.
==============
A. 30%
B. 33%
C. 50%
D Cannot be determined from the information given.