A compound event consists of two or more single events occurring together, such as flipping a coin and rolling a die. To calculate the probability of a specific compound event, one should make a list of all possible outcomes and count the number of outcomes that satisfy the compound event. For example, if tossing a coin and rolling a die, the probability of getting tails on the coin and an odd number on the die is 3/12, as there are 3 favorable outcomes out of the total 12 possible outcomes.

1. Compound Events Tuesday, February 23, 2010

2. What is that? A compound event consists of two or more single events. An example of this would be flipping a coin and rolling a die.

3. Finding Probabilities of Compound Events Let’s say you toss a penny and roll a die. Both are “fair” objects. What is the probability that the coin will show tails and the die will show an odd number? Here’s a hint….make a list!!!

4. Make a list of all the possible outcomes: Roll a 1, land on heads Roll a 1, land on tails Roll a 2, land on heads Roll a 2, land on tails 3h 3t 4h 4t 5h 5t 6h 6t

5. Now, using that list, choose the outcomes that have an odd number on the die and tails on the coin. These are 1t, 3t, and 5t; three possible outcomes Therefore, P(odd, tails) = 3/12 or ¼

6. Using the same die and coin, find the probability of the die showing a 2 and the coin showing heads. Make a new list…or just use the old one! P(2, heads) = 1/12