Video Transcript
The following Venn diagram shows two events π΄ and π΅. Determine π΄ minus π΅.
In order to answer this question, we will begin by listing the elements in event π΄ and event π΅. Circle π΄ in the Venn diagram contains the integers one, two, three, five, and eight. And we can write these elements using set notation as shown. In the same way, event π΅ contains the integers one, three, four, six, and nine. Two of these numbers, one and three, appear in both sets. This means that the intersection of π΄ and π΅ contains the numbers one and three.
In this question, we are trying to determine π΄ minus π΅. This is all the elements that are in set π΄ but not set π΅. π΄ minus π΅ is therefore the set containing the numbers two, five, and eight. This leads us to the difference rule, which states that π΄ minus π΅ is equal to π΄ minus π΄ intersection π΅. We can also use this rule to help determine probabilities of events.