SOLUTION: how do I solve probability of compound events like this: P(male or ninth grader) if this is the problem: A student is selected at random from a group of male a

Question 28924: how do I solve probability of compound events like this:
P(male or ninth grader)
if this is the problem:
A student is selected at random from a group of male and female students in the seventh, eighth, or ninth grade.

Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
Prob (male or ninth grader)=Prob(male)+Prob(ninth grader)-Prob (male and ninth grader)
Notice: "male and ninth grader" means a ninth grader who is male.
Cheers,
Stan H.
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