Probability Notes
Probability: The likelihood that an event will happen. You can
describe probability with words such as impossible, unlikely, likely,
and certain.
Certain Outcomes: If something is certain, it will ALWAYS happen. The
probability of it happening is 1.
Likely Outcomes: If something is likely, it will probably happen
(although it isn’t guaranteed).
Unlikely Outcomes: If something is unlikely, it probably won’t
happen.
Impossible Outcomes: If something is impossible, it will NEVER
happen. The probability of it happening is 0.
Which is more likely to happen:
____ You know someone with a birthday in December. OR
____ You know your great-grandmother’s birthday.
Which is unlikely to happen:
____ You will get a game for your birthday.
____ You will get a new car for your birthday.
Which is certain to happen:
____ You will blink your eyes today.
____ You will sneeze today.
Which is impossible to happen:
____ George Washington will come and teach you about the
Revolutionary War.
____ We’ll read about George Washington while studying the
Revolutionary War.