part 2 is completed

Author: RomanSanaye

number-systems/Part-2.md

@@ -7,16 +7,17 @@ The goal of these exercises is for you to gain an intuition for binary numbers.
 The answers to these questions will require a bit of explanation, not just a simple answer.
 
 Q16: How can you test if a binary number is a power of two (e.g. 1, 2, 4, 8, 16, ...)?
-Answer:
+Answer: A power of two in binary always has only one 1.
 
 Q17: If reading the byte 0x21 as an ASCII character, what character would it mean?
-Answer:
+Answer: In the ASCII table 0x21 is !.
 
 Q18: If reading the byte 0x21 as a greyscale colour, as described in "Approaches for Representing Colors and Images", what colour would it mean?
-Answer:
+Answer: 0x21 = 2 \*16 + 1 = 33 decimal => darkgray => 0 black - 255 white;
 
 Q19: If reading the bytes 0xAA00FF as a sequence of three one-byte decimal numbers, what decimal numbers would they be?
-Answer:
+Answer: splitting the memory into 3 separate 8-bit values ==> AA 00 FF ==>
+170, 0, 255;
 
 Q20: If reading the bytes 0xAA00FF as an RGB colour, as described in "Approaches for Representing Colors and Images", what colour would it mean?
-Answer:
+Answer: strong blue + some red ==> RGB(170, 0, 255)