Let \( S = \{1, 2, 3\} \) and \( T = \{3, 4, 5\} \) be two sets of numbers. What is the union of these two sets?

Step 1 ：Step 1: Identify the distinct elements in the two sets. In set \( S \), we have 1, 2, and 3. In set \( T \), we have 3, 4, and 5. Notice that 3 is a common element.

Step 2 ：Step 2: Combine all the distinct elements from both sets to form the union. This gives us 1, 2, 3, 4, and 5.