Consistent instructions and examples

I started off with "hints" that required the poor student to piece
together the information from incomplete bits. A complete example is
like a picture that is worth 1000 words and far clearer.

03_assignment.zig

@@ -1,14 +1,32 @@
 //
-// Oh dear! It seems we got a little carried away making const u8 values.
-//     * const means constant (cannot be changed)
-//     * u8 means unsigned (cannot be negative), 8-bit integer
+// It seems we got a little carried away making everything "const u8"!
 //
-// Hint 1: Use 'var' for values that can change.
-// Hint 2: Use enough bits to hold the value you want:
-//             u8             255
-//             u16         65,535
-//             u32  4,294,967,295
-// Hint 3: Use 'i' (e.g. 'i8', 'i16') for signed integers.
+//     "const" values cannot change.
+//     "u"     types are "unsigned" and cannot store negative values.
+//     "8"     means the type is 8 bits in size.
+//
+// Example: foo cannot change (it is CONSTant)
+//          bar can change (it is VARiable):
+//
+//     const foo: u8 = 20;
+//     var bar: u8 = 20;
+//
+// Example: foo cannot be negative and can hold 0 to 255
+//          bar CAN be negative and can hold −128 to 127
+//
+//     const foo: u8 = 20;
+//     var bar: i8 = -20;
+//
+// Example: foo can hold 8 bits (0 to 255)
+//          bar can hold 16 bits (0 to 65,535)
+//
+// You can do just about any combination of these that you can think of:
+// 
+//     u32 can hold 0 to 4,294,967,295
+//     i64 can hold −9,223,372,036,854,775,808 to 9,223,372,036,854,775,807
+//
+// Please fix this program so that the types can hold the desired values
+// and the errors go away!
 //
 const std = @import("std");