Independence and the AND rule
Pages
Independent events
Events where one outcome gives no information about the other.
The AND rule for independent events
Multiplying the probabilities of independent events for both-happen questions.
The independence assumption
The unstated assumption behind multiplying, and everyday cases where it fails.
Choosing between adding and multiplying
Deciding whether a worded question wants either event or both events.
The probability of at least one
One minus the probability of none, and why the complement beats listing cases.
Practice
Practice
Independent events
Events where one outcome gives no information about the other.
PracticeThe AND rule for independent events
Multiplying the probabilities of independent events for both-happen questions.
PracticeThe independence assumption
The unstated assumption behind multiplying, and everyday cases where it fails.
PracticeChoosing between adding and multiplying
Deciding whether a worded question wants either event or both events.
PracticeThe AND and OR rules review
Independent and dependent events, and when to multiply or add.