Independent and dependent events worksheet for Statistics
Statistics treats independence as something to check, not assume: A and B are independent exactly when P(A and B) equals P(A) × P(B). The bag questions set up the multiplication rule with and without replacement, and then the same test decides whether two events are related.
Also taught in Algebra 2, Geometry and Precalculus, each at its own level and with its own examples.
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Sigma Prep · sigmaprep.io/worksheets Name Independent and Dependent Events Date Period Find each probability, or answer as asked.
Free math worksheets at sigmaprep.io/worksheets© 2026 Sigma Prep |
Sigma Prep · sigmaprep.io/worksheets Name Independent and Dependent EventsAnswer keyVersion 3 Date Period Find each probability, or answer as asked.
Free math worksheets at sigmaprep.io/worksheets© 2026 Sigma Prep |
How to do these
, , and and . Are A and B independent?
- If they were independent, P(A and B) would be 0.4 × 0.5 = 0.2.
- The actual value is 0.25, which is not 0.2.
The answer is No: .
Where students go wrong
Reusing the first fraction after a draw without replacement. With 13 red among 21 counters, once a red is out there are 12 red among 20, so P(both red) is 13/21 × 12/20, not 13/21 × 13/21.
Also called with and without replacement, compound probability or multiplying probabilities.
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. →
- Independent or dependent?
- A spinner is spun twice. A: the first spin lands on blue. B: the second spin lands on blue. Are A and B independent or dependent? → Independent
- 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). →
- Independent? From P(A | B) or P(not A)
- , , and . Are A and B independent? → No:
- Independent events: find the missing probability
- A and B are independent. and not . Find and →
- Conditional probability with P(A or B)
- , , and or . Find →
- Working back to a probability
- A and B are independent. P(A) = 0.5 and P(A or B) = 0.85. Find P(B). → 0.7