Count From Two Tables

I have two tables. I have three columns DEPARTMENT_NAME, LAST_NAME, JOB_ID.

DEPARTMENT_NAME is from table

1. JOB_ID and LAST_NAME are from table 2.

I would like to count the number of employees for each DEPARTMENT_NAME and I want to be displayed DEPARTMENT_NAME, LAST_NAME, JOB_ID. But all I can do is to find the number of employees for each job_id. One DEPARTMENT_NAME has more than one JOB_ID.

Here is my code:
SELECT E.JOB_ID, D.DEPARTMENT_NAME, COUNT(E.LAST_NAME)
FROM EMPLOYEES E JOIN DEPARTMENTS D
ON (E.DEPARTMENT_ID = D.DEPARTMENT_ID)
GROUP BY E.JOB_ID, D.DEPARTMENT_NAME;