Probability of a Union of 3 Events

If you have 3 events A, B,  and C, and you want to calculate the union of both events, use this calculator.  This also calculates P(A), P(B), P(C), P(A Intersection B), P(A Intersection C), P(B Intersection C), and P(A Intersection B Intersection C).  The formula for the union Probability of A or B or C is denoted as:

P(A U B U C) = P(A) + P(B) + P(C) - P(A Intersection B) - P(A Intersection C) - P(B Intersection C) + P(A Intersection B Intersection C).

EXAMPLE:  You sponsor a ticket contest.  It's not stated that people can draw 1 or 2 tickets, you just sit back and let them draw.  The probability of a person picking red is 0.44.  The probability of a person picking blue is 0.24.  The probability of a person picking yellow is 0.21.  The probability the person draws a red and blue is 0.08.  The probability a person draws a red and yellow is 0.11.  The probability a person draws a blue and yellow is 0.07.  What is the probability that a person draws at least 1 of the colors, red, blue, or green?  Let A be a red draw, B be a blue draw, and C be a yellow draw.

Press P(A U B U C) and enter .44 or 0.44 for P(A), .24 or 0.24 for P(B), and .21 or 0.21 for P(C), .08 or 0.08 for P(A Intersection B), .11 or 0.11 for P(A Intersection C), and .07 or 0.07 for P(B Intersection C).  Press Calculate and your answer is 0.660.