improve wording

Author: atk

exercises/jigsaw-puzzle/instructions.md

@@ -1,16 +1,19 @@
 # Instructions
 
-You get part of the information and need to fills in the blanks.
-In case the data is insufficient or contradictory the user needs to be notified of the issue.
+Given partial information about a jigsaw puzzle, complete the remaining details.
+
+If the information is insufficient to complete the details, or if it contains contradictions, the user should be notified.
+
 The full information about the jigsaw puzzle contains the following parts:
 
-- `pieces`: Number of pieces
+- `pieces`: Total number of pieces
 - `border`: Number of border pieces
 - `inside`: Number of inside pieces
-- `rows`: Number of rows of pieces
-- `columns`: Number of columns of pieces
-- `aspectRatio`: Aspect ratio of columns / rows
+- `rows`: Number of rows
+- `columns`: Number of columns
+- `aspectRatio`: Aspect ratio of columns to rows
 - `format`: Puzzle format, which can be `portrait`, `square`, or `landscape`
 
 For the sake of the exercise, you may assume square pieces, so that the format can be derived from the aspect ratio.
+
 If it is lower than one, it is portrait, if exactly one, it is square and larger than one is landscape.