part 2 number system

Author: Boshra Mahmoudi

number-systems/Part-2.md

@@ -7,16 +7,18 @@ 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: If there is just one 1 in a binary number, then it is a power of 2. This is because each bit represents a power of 2, so if there is just one 1 bit in a binary number, the value represents a power of 2.
 
 Q17: If reading the byte 0x21 as an ASCII character, what character would it mean?
-Answer:
+Answer: !
 
 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: It represents 33, which is in the range of 0–255 from dark to light. This value represents a very dark grey.
 
 Q19: If reading the bytes 0xAA00FF as a sequence of three one-byte decimal numbers, what decimal numbers would they be?
-Answer:
+Answer:  three one-byte => 
+AA | 00 | FF ==> AA : 10 * 16 + 10 * 1 = 170 | 00 : 0 * 16 + 0 * 1 = 0 | FF : 15 * 16 + 15 * 1 = 255
+so it reperesnt 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: AA => 170 Red,  00 => 0 green , FF : 255 is blue