Please write all queries

Write SQL Queries for the following statements [ Assume required Database scheme as per need] 1. Delete duplicate rows from a table. 2. Display an alternate row from a table. 3. Delete an alternate row from a table. 4. Update multiple rows using a single update statement. 5. Find 3rd highest and 3rd lowest paid salary. 6. Display Nth rows from a table. 7. Display the ename which is started with j,k,l or m. 8. Show the list of all employees who were hired the first half of the month. 9. Write a trigger to ensure that no employee of an age less than 25 can be inserted in the database. 10. Write a trigger to count the number of new tuples inserted using each insert statement. 11. Create a view to generate employee salary statements with emp_id, HRA, DA, TA, Net_Salary fields