diff --git a/homeworks/02-goodreads/tfidf.md b/homeworks/02-goodreads/tfidf.md
index 3d96bd8b..eeb7cc26 100644
--- a/homeworks/02-goodreads/tfidf.md
+++ b/homeworks/02-goodreads/tfidf.md
@@ -34,7 +34,7 @@ Book Z with description "crime murder mystery club"
 Отговор:
 
 ```
-IDF('superhero',All books) = log(3/2) = log(1.5) = 0.17
+IDF('superhero',All books) = log10(3/2) = log10(1.5) = 0.17
 ```
 
 ### TF-IDF