What will be the output of the following query?select INSTR('Tech on the net', 'e', 1, 3) from dual;

The output of the query will be 11.

Here's the step by step explanation:

1. The INSTR function in SQL is used to search a string for a substring and returns the position of the substring in the string.

2. The syntax of the INSTR function is: INSTR(string, substring, start_position, nth_appearance)

3. In your query, you are searching for the substring 'e' in the string 'Tech on the net'.

4. The 'start_position' is 1, which means the search starts from the first character of the string.

5. The 'nth_appearance' is 3, which means the function will return the position of the third appearance of 'e' in the string.

6. The 'e' appears at the 2nd, 6th and 11th positions in the string 'Tech on the net'.

7. Therefore, the function will return 11, which is the position of the third 'e' in the string.