The multiplication rule - the probability of two events both happening, P ( A and B), is equal to P(A)P (BIA ). - If events A and Bare independent, this simplifies to PLACE!! The addition rule - the probability of either one of two events happening. ? (for B). is equal to PLA) + P(B) - P ( A and B ). > If events A and B are mutually exclusive, this simplifies to P(A) + PUB). Example Spinner: A spinner has 4 equal sectors colored yellow, lelue green, and red. ( a) what is the probability the spinner lands on yellow? (6) what is the probability the spinner lands on red or blue? ( f) what is the probability the spinner does NOT land on green