Impossible Event
An impossible event is an event that cannot occur in a given random experiment because it contains no favorable outcomes. According to theoretical probability, the probability of an impossible event is always exactly zero.
Key Concepts
In any random experiment, if the condition for an event does not match any outcome in the sample space, it is classified as an impossible event.
The number of favorable outcomes for an impossible event is always zero.
It represents the absolute lower limit of the probability range, reinforcing the rule that probability can never be a negative value.
Formula & Equation
P(E) is the probability of the impossible event E, n(E) is the number of favorable outcomes which is exactly 0, and n(S) is the total number of possible outcomes in the sample space.
Common Misconceptions
Myth: An event with a very low probability, like winning a massive lottery, is considered an impossible event.
Fact: An impossible event has a probability of exactly zero and cannot happen under any circumstances. A highly unlikely event still has a probability greater than zero and can theoretically occur.
Myth: The probability of an impossible event can be a negative number.
Fact: Probability values are strictly restricted to the range of 0 to 1. The lowest possible probability is 0, which corresponds to an impossible event. Negative probability does not exist.
Real World Applications
Rolling a standard six-sided die and getting a number greater than 6, such as a 7 or 8.
Drawing a green card from a standard playing card deck, which only contains red and black suits.
Tossing a single coin once and getting both heads and tails simultaneously.
Frequently Asked Questions
What is the probability of an impossible event?
The probability of an impossible event is always 0, meaning there is absolutely no chance of it occurring during the experiment.
How do you identify an impossible event in a sample space?
You can identify an impossible event if the specific condition or outcome you are looking for does not exist within the defined sample space of the random experiment.