Event Counter

The Event Counter counts the number of ways that two or more independent events can occur simultaneously.


  • Specify the number of independent events (n).
  • Enter the number of different ways each independent event can occur.
  • Click the Calculate button to compute the number of event multiples.
Number of independent events ( n )
Number of ways event 1 can occur
Number of event multiples

What is an event multiple?


On this website, we refer to a grouping of two or more independent events as an event multiple. Many problems in statistics require a count of the number of unique event multiples that can be created from independent events.

For example, suppose one event is the outcome of a coin flip - heads or tails. Another event is the outcome from throwing a dart - hit or miss. These two events can be combined in four different ways - heads/hit, heads/miss, tails/hit, and tails/miss. Therefore, in this example, there are four possible event multiples.

This calculator, the Event Counter, counts the number of unique event multiples that can be created from two or more independent events. For an example that demonstrates event multiples, see the sample problem below.

See also:    Rules of Counting

Sample Problem


  1. On holidays, Chef Alice serves a dinner special consisting of a drink, an entree, and a dessert. Customers can choose from 5 drinks, 8 entrees, and 3 desserts. How many different meals can be created from the dinner special?

    Solution:

    The solution to this problem involves counting the number of event multiples. We know the following:

    • Each dinner consists of 3 independent events - a drink, an entree, and a dessert.
    • Customers can choose from 5 drinks, 8 entrees, and 3 desserts.

    The number of event multiples would be (5)(8)(3) = 120. Thus, 120 different meals can be created from the dinner special. To solve this problem using the Event Counter, do the following:

    • Enter "3" for "Number of independent events".
    • Enter "5" for "Number of ways event 1 can occur".
    • Enter "8" for "Number of ways event 2 can occur".
    • Enter "3" for "Number of ways event 3 can occur".
    • Click the "Calculate" button.

    The answer, 120, is displayed in the "Number of event multiples" textbox.