An event is a set of outcome to which a probability is assigned. There are different types of events in probability explained below.

Independent EventsIf the outcome of the first event is not influenced by the outcome of the second event, then the two events are said to be independent. Probability of two events are determined by multiplying the probability of the first event by the probability of the second event.

If A and B are independent events, P(A and B) = P(A) . P(B)

__Dependent Events__Two events are dependent, if the outcome of the first affects the outcome of the second, where the probability will be changed. When two events A and B are dependent, and A occur first. The probability of both occurring is P(A and B) = P(A) $\times$ P(

$\frac{B}{A}$)

Dependent events are of two types as follows

**With Replacement:** When the sample is drawn, object is placed back where it was taken from and if subsequent draws are made, it could be selected again.

**Without Replacement:** When the sample is drawn, object will not be placed back from where it was taken, which results to change in probability, when the subsequent draws are made.

__Elementary Event__ An elementary event is any single element of a sample space. Elementary events are also known as atomic events. **Example:** When a die is thrown, an elementary event would be 5.

__Compound Event__An event that includes two or more independent events is called a compound event. **Example:** Event of obtaining the same side (both heads or both tails), when a coin is tossed twice. A = {HH, TT}

__Impossible Event__Impossible event does not contain any element.**Example:** When two coins are tossed simultaneously and obtaining three heads.

__Disjoint or Mutually Exclusive Events__

Two events A and B are disjoint or mutually exclusive, when they don't have an element in common.

**Example:** Turning left and turning right are mutually exclusive. (Both can't be done at the same time).

Sure EventSure event S, is formed by all possible results of the sample space.**Example:** Rolling two die and having a score of less than 13.

__Exhaustive Event__One or more events are said to be exhaustive, if all the possible elementary events under the experiment are covered by the events considered together. It can be equally likely or not equally likely.