Chapter 3: NUMBER SYSTEM AND THEIR CONVERSION
Short Answer Questions
1. Convert 333₁0 Denary numbers into Hexadecimal and back to base two number system.
First converting, decimal to hexadecimal,
| 16 | 333 | Remainder
13=D |
| 16 | 20 | 4 |
| 16 | 1 | 1 |
| 0 |
Hence, (333)10 = (14D)16
Now, converting back to base two number system (i.e. binary number system)
Arranging in 4-bits,
| Hexadecimal | 1 | 4 | D |
| Binary | 0001 | 0100 | 1101 |
Hence, (14D) 16 = (000101001101)2
2. Convert the following numbers according to the given instruction
- 24010 into Octal number

Hence, (240)10 = (360)8
- ABC16 in to Binary number.
Arranging in 4-bits,
| Hexadecimal | A | B | C |
| Binary | 1010 | 1011 | 1100 |
Hence, (ABC) 16 = (101010111100)2
3. What is octal number system? Convert 35610 int base 8.
Octal number is a base 8 number system. It uses 8 digits (0, 1, 2, 3, 4, 5 6 and 7). Base of this number system is 8 or 0.
Example: (405)s or (405)o.
For second part of the question,

Hence, (356)10 = (544)8
4. What is binary number system? Convert 52010 into base 16.
Binary number system is a base 2 number system. It uses 2 digits, 0 and 1. It is the only number system, which is directly understood by the computer. Example: (10101)2 or (10101) B
For second part of the question,

Hence, (520)10 =(208)16
5. What is hexadecimal number system? Convert 11 10 112 into base 16.
Hexadecimal number system is a base 16 number system. It uses 16 digits, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E and F.
Example: (A05)16 or (A05)H. For second part of the question,
Grouping into 4 bits, 0011 1011
| Binary | 0011 | 1011 |
| Hexadecimal | 3 | B |
Hence, (111011) 2= (3B)16
42.2074 Set A Q.No. 14 OR Subtract (10011), from (11110), by using 1’s and 2’s complement method.
Subtracting (11110)2 – (10011)₂
[Using 1’s complement method]
1’s complement of 10011 = 01100
Adding it with minuend (i.e. 11110) = 11110
+ 01100
101010
Since, there exists’ one additional bit,
Difference= 01010
+1
01011
Hence, 11110 – 10011 = (01011)2.
[Using 2’s complement method]
2’s complement of 10011
= 01100
+1
01101
Adding it with 11110 = 11110
+01101
101011
Since, there exists’ one additional bit, Difference = 01011 (Neglect additional bit i.e. 1)
Hence, 11101 – 10011 = (01011)2.

