[johnny]

Any suggestion would be appreciated.

1. What would be the hexadecimal representation of the largest memory address in a memory consisting of 4MB if each cell had a one-byte capacity?
I answered:
(didn't answer, because I don't know the answer)
2. If the message
xxy yyx xxy xxyy
were compressed using LZW with a starting dictionary whose first, second, and third entries were x, y, and space, respectively, what would be the entries in the final dictionary?
I answered:
112322134342
3. One means of transmitting bits over traditional telephone systems is to convert the bit patterns into sound, transfer the sound over the telephone lines, and then convert the sound back into bit patterns. Such techniques are limited to transfer rates of 57.6 Kbps. Is this sufficient for teleconferencing if the video is compressed using MPEG?
I answered:
Since 40Mbps = 40 x 10^6 bps = 40000 x 10^3 bps = 40000Kbps, hence the answer is no (not sufficient for teleconferencing).
4. Encode the following sentence in ASCII using one byte per character. Use the most significant bit of each byte as an (odd) parity bit.
100/5 = 20
I answered:
00110001 10110000 10110000 00101111 10110101 00100000 00111101 00100000 00110010 10110000
5. The following message was originally transmitted with odd parity in each short bit string. In which strings have errors definitely occurred?
I answered:
11001, 10011, 10110, 11111, 10001, and 10101.
6. Suppose a 24-bit code is generated by representing each symbol by three consecutive copies of its ASCII representation (for example, the symbol A is represented by the bit string 010000010100000101000001). What error-correcting properties does this new code have?
I answered:
Have three odd parity every third interval of string, if required.
7. In the following case, the different bit strings represent the same value but in different numeric encoding systems. Identify each value and the encoding systems used to represent it.
11111010 0011 1011
I answered:
(didn't answer, because I don't know the answer to it)