Your answer, "550", is not correct.
The correct answer to
How many cheif officers were over Solomon's work?
is
250
as shown by
2 Chronicles 8:10
which is
- KJV
- And these were the chief of king Solomon's officers, even two hundred and fifty, that bare rule over the people.
- NIV
- They were also King Solomon's chief officials--two hundred and fifty officials supervising the men.