What have you tried so far?
And looking at the Table structure, I don't even find the salary column itself. So, how do you know what the Salary is.
The current table structure is not even normalised.
Anyway, if I were you I would first restructure the tables as:
Employee:
Id,
Name,
Age,
Salary,
DepartmentId
Department:
Id,
Name
Apart from that I would suggest you to look at following topics (atleast) in SQL:
MAX
http://www.w3schools.com/sql/sql_join.asp[
^]
GroupBy
http://www.w3schools.com/sql/sql_groupby.asp[
^]
Joins
http://www.w3schools.com/sql/sql_join.asp[
^]
I suggest you try it out writing yourself and show us what have you tried. And if you still have questions, someone here would help you.