Quiz & Worksheet - The Addition Rule of Probability 1. Grace, Avery, and Noah are creating a maze for their pet gerbil, Sam. Grace bets that Sam will turn left when
first entering the maze. Avery bets that Sam will turn right, and Noah bets that Sam will go straight. If there's an
equal chance of Sam taking one of the given paths, then what is the probability that Grace or Noah will be
correct?
27
1/2
13
21
20
2. Melissa collects data on her college graduating class. She finds out that of her classmates, 60% are brunettes,
20% have blue eyes, and 5% are brunettes that have blue eyes. What is the probability that one of Melissa
classmates will be a brunette or have blue eyes?