pls solve all the questions using psql

Consider the business trip database that keeps track of the business trips of salesman in an office. Following are the tables: SALESMAN (SNO INTEGER, S_NAME CHAR (30), START_YEAR YEAR) TRIP (TNO INTEGER, FROM_CITY CHAR (20), TO_CITY CHAR(20), DEPARTURE_DATE DATE, RETURN DATE) DEPT (DEPTNO VARCHAR (10), DEPT_NAME CHAR(20)) EXPENSE (EID INTEGER, AMOUNT MONEY) The relationship is as follows DEPT-SALESMAN 1 TO M SALESMAN - TRIP 1 TO M TRIP - EXPENSE 1 TO 1 a) Write a function to display names of salesman from 'Home appliances' department. b) Write a PL/pgsql function to find a business trip having maximum expenses. c) Write a function to delete information of all trips to 'pune' city d) Write a function increase expense of all the trips by 50000 e) Write a function to update the departure date for given trip number (accept trip no and new departure date from user)