Probability of compound events worksheet for Algebra 2
Three rules that cover most of the topic: and means multiply, or means add and then take off the overlap, and drawing without replacement changes the second fraction.
Also taught in Precalculus, Geometry and Statistics, each at its own level and with its own examples.
Select your difficulty
Pick more than one for a sheet that mixes them.
The preview can look cramped on a phone. The PDF and printed sheet come out normal.
Free math worksheets at sigmaprep.io/worksheets© 2026 Sigma Prep
Sigma Prep · sigmaprep.io/worksheets Name Probability of Events Date Period Find each probability.
Free math worksheets at sigmaprep.io/worksheets© 2026 Sigma Prep |
Sigma Prep · sigmaprep.io/worksheets Name Probability of EventsAnswer keyVersion 1 Date Period Find each probability.
Free math worksheets at sigmaprep.io/worksheets© 2026 Sigma Prep |
How to do these
A bag has 4 red and 6 blue counters. Two are drawn without replacement. Find P(both red).
- The first draw is 4 out of 10.
- One red is gone, so the second is 3 out of 9.
- Multiply.
The answer is .
Where students go wrong
Using the same fraction twice when there is no replacement. The second draw happens in a smaller bag with one fewer of whatever you took, and forgetting that is the single most common error on this topic.
Also called independent events, dependent events or compound probability.
What you can put on this worksheet
- Independent events: both the same
- A spinner has 9 equal sections: 4 red and 5 blue. It is spun twice. Find the probability that it lands on red both times. →
- Independent events: one of each
- A spinner has 9 equal sections: 4 red and 5 blue. It is spun twice. Find the probability that it lands on red once and blue once. →
- Dependent events: both the same
- A class has 4 girls and 5 boys. To pick who hands out papers, the teacher draws two names from a hat, one after the other. Find the probability that both are girls. →
- Dependent events: one of each
- A class has 4 girls and 5 boys. To pick who hands out papers, the teacher draws two names from a hat, one after the other. Find the probability that the two are one of the girls and one of the boys, in either order. →
- One event or the other
- A 6-sided die is rolled. Find P(greater than 3 or less than 3). →
- Probability with combinations
- A box has 3 winning tickets out of 10. Two are drawn at once. Find P(neither is a winner). →
- Experimental probability
- A spinner was spun times and landed on red on of the spins. Find the experimental probability of landing on red. →
- At least one, by the complement
- A die is rolled 3 times. Find P(at least one 5). →
- Two different experiments: a coin and a die, a die twice
- A spinner with 5 equal sections numbered 1 to 5 is spun twice. Find P(a 5, then an even number). →
- Three picks in a set order
- A drawer has 4 black, 2 gray and 3 white socks. Three are taken at random, one after another, without putting any back. Find P(black, then black, then black). →
- Drawing from two groups: exactly so many
- A standard 52-card deck has 26 red cards and 26 black cards. Three cards are dealt at random. Find exactly 3 red. →
- Coins, dice and guessing: exactly, at least, at most
- A student guesses on every question of a 4-question true-false quiz. Find P(at most 1 right answer). →