1. Use the basic definition of probability Yes Do you know what the entire sample space looks like? No P(A) Yes #ways A can occur # possible outcomes in Sample Space P(A or B) = P(A) + P(B) Are the events OR mutually exclusive? No P(A or B) = P(A) + P(B) P(A and B) Yes Are the events AND Independent? You need a formula, what type of probability are you trying to calculate? Conditional 2. P(A and B) = P(A) P(B) No | P(A and B) = P(A) P(B|A) P(A|B)= P(A and B) P(B) 2. For each probability question, fill in the table explaining which formula is appropriate to solve the problem, then explain why it is the correct formul. Explanation Problem From Correct for WHY it is Formula to the correct Use formula Practice Worksheet 1a 1b 1c 1d 1e 2 3 4 5a 5b