diff --git a/education/software development/ECE1400/Chapter 7 Exercises.md b/education/software development/ECE1400/Chapter 7 Exercises.md
index 23806b5..5f2538d 100644
--- a/education/software development/ECE1400/Chapter 7 Exercises.md	
+++ b/education/software development/ECE1400/Chapter 7 Exercises.md	
@@ -3,4 +3,24 @@
 a. `short unsigned int`
 b. `short float`
 c. `long double`
-d. `unsigned long`
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+d. `unsigned long`
+
+Answer:
+b. `short float`
+
+> 4. If `c` is a variable of type `char`, which of the following statements is illegal?
+
+```c
+char c;
+// A:
+i += c; // i has type int
+// B:
+c = 2 * c - 1;
+// C:
+putchar(c);
+// D:
+printf(c);
+```
+
+Answer:
+D is incorrect because `printf` operates on strings.
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