CBSE Class 11 Computer Science Question 52 of 68

Data Representation and Boolean Logic — Question 23

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23
Question

Question 23

Express the following octal numbers into their equivalent decimal numbers.

(a) 145

(b) 6760

(c) 455

(d) 10.75

Answer

(a) 145

Octal
No
PowerValueResult
5 (LSB)8015x1=5
48184x8=32
1 (MSB)82641x64=64

Equivalent decimal number = 5 + 32 + 64 = 101

Therefore, (145)8 = (101)10.

(b) 6760

Octal
No
PowerValueResult
0 (LSB)8010x1=0
68186x8=48
782647x64=448
6 (MSB)835126x512=3072

Equivalent decimal number = 48 + 448 + 3072 = 3568

Therefore, (6760)8 = (3568)10.

(c) 455

Octal
No
PowerValueResult
5 (LSB)8015x1=5
58185x8=40
4 (MSB)82644x64=256

Equivalent decimal number = 5 + 40 + 256 = 301

Therefore, (455)8 = (301)10.

(d) 10.75

Integer part:

Octal
No
PowerValueResult
0 (LSB)8010x1=0
1 (MSB)8181x8=8

Equivalent decimal number = 8

Fractional part:

Octal
No
PowerValueResult
7 (LSB)8-10.1257x0.125=0.875
5 (MSB)8-20.0156255x0.015625=0.078125

Equivalent decimal number = 0.875 + 0.078125 = 0.953125

Therefore, (10.75)8 = (8.953125)10.