diff --git a/education/software development/ECE1400/Chapter 7 Exercises.md b/education/software development/ECE1400/Chapter 7 Exercises.md
index 4e1248b..c0d1144 100644
--- a/education/software development/ECE1400/Chapter 7 Exercises.md	
+++ b/education/software development/ECE1400/Chapter 7 Exercises.md	
@@ -38,4 +38,11 @@ D. Seconds in a day: `long`
 Answer:
 `unsigned int`
 
-> 15. 
\ No newline at end of file
+> 15. Use `typedef` to create types named `Int8`, `Int16`, and `Int32`. Define the types so that they represent 8 bit, 16 bit, and 32 bit integers on your machine.
+
+Answer:
+```C
+typedef char Int8;
+typedef short Int16;
+typedef long Int32;
+```
\ No newline at end of file