CSCE 101 Final Exam

44. Explain the concept of the software life cycle.

5 phases: 1. Requirements 2. Specification 3. Design 4. Implementation 5. Maintenance

42. How many bits does a byte contain?

8 bits = 1 byte

53. Define polynomial time.

Any algorithm whose order of magnitude can be expressed as a polynomial in the size of the problem is known as polynomial time algorithm. Order of magnitude is shown as the size of the problem to a power.

31. Define representational error, cancellation error, underflow, and overflow. Discuss how these terms are interrelated.

Representational error - Caused when the accuracy and result of arithmetic operation is greater than the machine accuary, error is known as round-off error. Cancellation error - Arises when different sizes of numbers are operating in addition and subtraction and due to limit of precision, loss of accuracy happens Underflow - condition in program where result of an arithmetic operation is smaller than machine stored in the memory. Overflow - opposite, unable to read the calculation of any arithmetic expression due to very large size

32. Show the range of integer numbers that can be represented in each of the following word sizes: 8 bits 16 bits 24 bits 32 bits 64 bits

(-2^7, 2^7), (-2^15, 2^15), (-2^23, 2^23) (-2^31, 2^31), (-2^63, 2^63)

45. Where do most of the errors occur in a software project?

The design phase and the implementation phase are where most of the errors occur in a software project.

1. Lossless compression means the data can be retrieved without losing any of the original information.

True

12. Huffman encoding uses variable-length binary strings to represent characters.

True

15. The MP3 audio format discards information that cannot be heard by humans.

True

16. An RGB value represents a color using three numeric values.

True

7. Overflow occurs when the value that we compute cannot fit into the number of bits we have allocated for the result.

True (calculated value of an operation cannot fit in the space reserved for it)

23. Convert the following numbers from the base shown to base 10. 111 (base 2) 777 (base 8) FEC (base 16) 777 (base 16) 111 (base 8)

111 = 7 777 = 511 FEC = 4076 777 = 1911

33. How many things can be represented with Four bits? Five bits? Six bits? Seven bits?

16, 32, 64, 128

47. How many bits would be needed to represent a character set containing 45 characters? Why?

6 bits, so no overflow

43. How many bytes are there in a 64-bit machine?

8 bytes in a 64 bit machine

13. Binary numbers can be read off in hexadecimal but not in octal.

False

14. Starting from left to right, every grouping of four binary digits can be read as one hexadecimal digit.

False

5. Four bits can be used to represent 32 unique things.

False (16 = 2^3)

15. A byte is made up of six binary digits.

False (8 digits)

2. A computer represents information in an analog form.

False (digital form)

16. Two hexadecimal digits cannot be stored in one byte.

False (they can be)

58. How does pixel resolution affect the visual impact of an image?

Higher resolution means more pixels which increases image quality.

46. Why does the cost of fixing an error increase the longer the error remains undetected?

If there is an error in specification phase and you leave it, you may have to go through and correct it in the design and implementation phase.

28. What is the difference between lossless and lossy data compression?

Lossy - when there is a loss of information from the original data. Lossless - when there is no a loss of data from the compression

67. What is resolution?

Number of pixels used in an images

56. What is an RGB value?

Red, Green, Blue. 0-255. able to use these numbers to combine to form colors