Probability Word Problems

Probability problems ask you to figure out the chances of something happening — drawing a red marble from a bag, rolling a certain sum with two dice, or selecting a committee with specific characteristics. What makes these tricky isn't usually the math itself (which often comes down to counting and dividing) but correctly identifying what you're counting. You need to distinguish between "and" (multiply) and "or" (add), between "with replacement" and "without replacement," and between situations where order matters (permutations) and where it doesn't (combinations). Getting these distinctions wrong is easy and gives you an answer that feels right but isn't, which is exactly why these problems are so valuable for building mathematical reasoning.
Probability Without Replacement

Find probability both pens are non-defective when selecting 2 from 12 (3 defective). Use combinations.

Probability Without Replacement

Basket has 4 apples, 5 oranges, 2 bananas. Jonas picks one, Beth picks next. P(orange then apple)?

Roulette Probability: Gambler's Fallacy

Probability of red on roulette. Classic problem about independent events and the gambler's fallacy.

Two-Way Table Probability: Red Car or Ticket

Find P(red car OR speeding ticket) using a two-way frequency table. Learn inclusion-exclusion and conditional probability.