The terms "at least" as well as "or" I know they have their roles to play. Or means, "either one or the other, or both" And the term "At Least" better yet("At Least One"). To find this step you have 4 steps you must conduct, "Use the Symbol A to denote the event of getting at least One". Let A(Compliment) represent the event of getting none of the items being considered. Calculate the probability that None of the items considered" 3-Calculate the probability that none of the outcomes results in the event being considered. 4 Subtract the result from 1, that is evaluate this expression P(At least One)=1-P(None). They are 2 different steps, one is basically for the addition rule the other multiplication rule.
Now, I have a question(I don't want anybody to solve it, I will do that on my own) the question states, What is the Probability that if a single student is randomly selected they would have a GPA greater than or equal to 3.0 or be taking at least 8 units.
I haven't had a problem that has both symbols. Most of my HW has been OR, and also AT LEAST ONE. I have not had both, so I just want a stepping stone, not sure if I am going to be doing the addition method or another way. I have gone through my book, I haven't seen a problem like this.

