The Venn diagram shows the number of items in sets $Q$ and $R$, including their intersection. Here's how the values break down:

• The number 8 represents elements that are in neither $Q$ nor $R$.
• The number 5 represents elements that are in set $Q$ only.
• The number 7 represents elements that are in set $R$ only.
• The number 6 represents elements that are in both $Q$ and $R$ (the intersection of $Q$ and $R$).

To find how many items are in $Q \cup R$ (the union of $Q$ and $R$, meaning all elements in $Q$ or $R$, or both), we sum the relevant values:

$Q \cup R = 5 + 6 + 7 = 18$

Therefore, there are 18 items in $Q \cup R$.

Do you want further explanation or have any other questions?

Here are five related questions to expand your understanding:

1. How do you calculate the number of elements in $Q \cap R$?
2. What is the meaning of the complement of $Q \cup R$?
3. How many total elements are in the universal set $\xi$ in this diagram?
4. Can a Venn diagram represent more than two sets? How would you interpret it?
5. How would the answer change if there were additional sets intersecting $Q$ and $R$?

Tip: Always remember that in a Venn diagram, the union of two sets includes all the elements from both sets, but you should only count the elements in the intersection once.