Graphics assignment 9

Added space in questions.txt.

graphics/ass9/source/questions.txt

@@ -34,7 +34,7 @@ Question 3:
 	redundantly? Is there opportunity for parallel processing?
 
 	- There's plenty of room for parallel processing, since all cells/tetrahedons
-	  are checked independently of eachother.
+	  are checked independently of each other.
 	- If we know (by specification) that an isosurface is closed, we can use the
 	  property described in the answer to question 2 by creating an incremental
 	  algorithm that uses already interpolated points in neigbouring tetrahedons