Answers to Chapter 3 Review Questions

1. a) 2 b) 4 c) 7 d) 11 e) 12 f) 18 g) 21 h) 31 i) 205 j) 227

2. a) 111 b) 10011 c) 11100 d) 101110 e) 111001 f) 1010110 g) 1011110 h) 1110000 i) 10010100 j) 11100110

3. a) 30 b) 68 c) 80 d) 142 e) 240 f) 846

4. a) 111100 b) 10110000 c) 1001010000 d) 110100100 e) 10101101001 f) 10011000110100

5. a) 90 b) 199 c) 2485 d) 422

6. a) 1001100 b) 1101000 c) 11011010010 d) 1100011011

7. a) 0001 0100 0110 BCD b) 0011 1000 1001 BCD c) 0001 0110 0111 1000 BCD d) 0010 0101 0000 0010 BCD

8. Only one digit changes as you count up from zero

9. The binary system uses only the digits 0 and 1, and computer circuits can easily distinguish between the two voltage levels that correspond to the binary digits 0 and 1.

10. a) Each digit of a binary number b) A group of 8 bits c) A group of 1 or more bytes d) The digit that represents the smallest value e) the digit that represents the largest value

11. a) Base 8 b) Base 10 c) Base 2 d) Base 16

12. An extra digit used to represent the polarity of a binary number 13. The 1’s complement of a binary number is the number that results when all the 1’s are changed to 0’s and all the 0’s are changed to 1’s.

14. An alphanumeric code, which includes letters as well as numbers

15. To detect errors that may occur while a word is being moved

16. a) 1101 b) 1000 c) 10111

17. a) 1000 b) 11 c) 101

18. a) 100100 b) 1010 c) 1111

19. a) 101 b) 100 c) 11011