diff --git a/curriculum/challenges/english/10-coding-interview-prep/rosetta-code/top-rank-per-group.md b/curriculum/challenges/english/10-coding-interview-prep/rosetta-code/top-rank-per-group.md
index 1d108daccf..c9405c8f3f 100644
--- a/curriculum/challenges/english/10-coding-interview-prep/rosetta-code/top-rank-per-group.md
+++ b/curriculum/challenges/english/10-coding-interview-prep/rosetta-code/top-rank-per-group.md
@@ -48,6 +48,8 @@ one could rank the top-rated movie in each genre by calling
 
 `topRankPerGroup(1, data, 'genre', 'rating')`
 
+The function should return an array with an array for each group containing the top `n` objects.
+
 # --hints--
 
 `topRankPerGroup` should be a function.