SELECT dno, COUNT(ssn) FROM employee GROUP BY dno dno COUNT(ssn)   1 1 4 3 5 4 

Answer:
Fact: The result of a subquery is a relation In other words: (SELECT dno, COUNT(ssn) FROM employee GROUP BY dno) is a relation 

Solution:
From the above discussion, we can find the most number of employees in any dept as follows: select max(NEmps) from (select count(ssn) NEmps from employee group by dno) A max(NEmps)  4 

Solution  part 1: we first find the most number of dependents of any employee
1. Here are the dependents of each employee: SELECT * FROM dependent essn name sex bdate relationship      123456789 Micheal M 01JAN78 SON 123456789 Alice F 31DEC78 DAUGHTER 123456789 Elizabeth F 05MAY57 SPOUSE 333445555 Alice F 05APR76 DAUGHTER 333445555 Theodore M 25OCT73 SON 333445555 Joy F 03MAY48 SPOUSE 987654321 Abner M 29FEB32 SPOUSE 
Solution  part 2: find employees who has the most number of dependents
1. Here are the employees and their dependents: select fname, lname, name from employee, dependent where ssn=essn fname lname name    Frankl Wong Alice Frankl Wong Theodore Frankl Wong Joy Jennif Wallace Abner John Smith Alice John Smith Elizabeth John Smith Micheal 