From the image, we have a Venn diagram with the universal set $U$ and two subsets $A$ and $B$. Here is the breakdown of the elements:

• Set $A$ contains: $\{10, 46, 57\}$
• Set $B$ contains: $\{6, 13, 20, 37, 39\}$
• Elements outside $A$ and $B$ but in $U$ are: $\{5, 18, 26, 48\}$

To find the complete universal set $U$, we list all elements in $A$, $B$, and the elements outside of both sets:

$U = \{5, 6, 10, 13, 18, 20, 26, 37, 39, 46, 48, 57\}$

Would you like further details or explanations?

Here are some related questions that might deepen understanding:

1. What is the union of sets $A$ and $B$?
2. What is the intersection of sets $A$ and $B$?
3. How many elements are there in the universal set $U$?
4. Are sets $A$ and $B$ disjoint?
5. What is the complement of set $A$ within $U$?

Tip: When dealing with Venn diagrams, make sure to consider each part of the diagram (inside each set, outside, and overlaps) to fully determine the universal set.