Answer:
The converse statement is:
-  If the coordinates of a point are both negative, then the point is in Quadrant III. 
Explanation:
We know that for any conditional statement of the type:
 If p then q i.e. p → q
where p is the hypothesis and q is the conclusion.
The converse of the statement is given by:
 If q then p i.e. q → p.
 We are given a statement as:
If a point lies in Quadrant III, then its coordinates are both negative.
i.e. Here p=Point lie in Quadrant III
and q= Coordinates are both negative.
Hence, the converse statement will be:
 If the coordinates of a point are both negative, then the point is in Quadrant III.