diff --git a/education/software development/ECE1400/Chapter 15 Exercises.md b/education/software development/ECE1400/Chapter 15 Exercises.md
index d26c8bb..21d08cd 100644
--- a/education/software development/ECE1400/Chapter 15 Exercises.md	
+++ b/education/software development/ECE1400/Chapter 15 Exercises.md	
@@ -80,4 +80,4 @@ All source files, because they all include `f1.h`.
 
 > (d). If `f2.h` is changed after the program has been built, which files need to be recompiled?
 
-
+`f1.c` and `f2.c`.