Added book examples

C5/not_displaying.c

@@ -0,0 +1,17 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+int main(void)
+{
+
+    // Declare some variables
+    int a = 1, b = 2;
+    float f = 1.23f;
+
+    // Use printf display text on the screen
+    printf ("The variables are a, b and f");
+
+    // Exit from main
+    return 0;
+
+}