# Computer Aptitude Questions – 1’s Complement and 2’s Complement Numbers | Set 9

D.1-5): Convert the following numbers to one’s complement form.

Q.1) Convert the decimal number 45 to one’s complement form.

(a) 101101

(b) 010010

(c) 100010

(d) 010110

(e) 010001

Solution:

b

Step 1:

Convert the given number to binary number.

4510 = 1011012

Step 2: Invest the value of numbers “1 by zero” and “byone”

1011012 → 0100102

Q.2) What is the one’s complement of a number 0111001102?

(a) 100011101

(b) 000011001

(c) 110011001

(d) 100011001

(e) None of these

Solution:

d

011100110 → 100011001

Q.3) What is the one’s complement of a number 10001102

(a) 10110012

(b) 0111101

(c) 0111001

(d) 01100001

(e) 1001001

Solution:

c

1000110  → 0111001

Q.4) What is the one’s complement of a number 2810

(a) 100112

(b) 000012

(c) 110112

(d) 111002

(e) None of these

Solution:

e

Step 1: 2810 →  11100

Step 2: 11100  → 00011

Q.5) What is the one’s complement of a number 5610

(a) 111

(b) 110

(c) 1101

(d) 1111

(e) 000011

Solution:

a

Step 1: Binary conversion

5610  → 111000

Step 2: Invert the digits

111000  → 000111

D.6-10): Convert the following numbers to complemented numbers.

Q.6) 5810

(a) 1001

(b) 111

(c) 110

(d) 010

(e) 1110

Solution:

c

Step 1: Binary conversion => 5810   → 1110102

Step 2: Invert the digits => 111010  → 000101

Step 3: Add 1 with LSB

Q.7)100111012

(a) 01100011

(b) 1101100

(c) 1100010

(d) 1101110

(e) 1100001

Solution:

a

Step 1: Inert the digits

1001  11012 → 01100010

Step 2: Add 1 with LSB

Q.8) 2510

(a) 110

(b) 111

(c) 1101

(d) 100

(e) 101

Solution:

Step 1: Binary conversion: 2510 →11001

Step 2: Invert the digits  : 11001 →00110

Q.9) 9210

(a) 001100

(b) 101100

(c) 110100

(d) 100100

(e)101011

Solution:

Step 1: Binary conversion: 9210 → 1011100

Step 2: Invert the digits : 1011100 →01000112

Step 3: Add 1 with LSB

Q.10) 110111010112

(a) 111000101

(b) 111010101

(c) 100110101

(d) 110010101

(e) 100010101

Solution:

e

Step 1: Inert the digits

11011101011

Step 2: Add 1 with LSB