Information representation

Worked examples (6)

• 1Convert denary 77 to 8-bit binary
• 2Convert binary to hexadecimal (and to denary)
• 3Represent −45 in 8-bit two's complement
• 4Binary addition and detecting overflow
• 5Binary subtraction using two's complement
• 6Character encoding: ASCII codes and Unicode

Model answers (6)

• ✓Model answer — 9618 Paper 1 style
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Worked examples (6)

• 1Estimate the file size of a bitmap image
• 2Colour depth and number of colours
• 3Effect of increasing resolution and colour depth
• 4Estimate the file size of a sound recording
• 5Justify bitmap vs vector for a company logo
• 6Effect of changing sampling rate and resolution

Model answers (6)

• ✓Model answer — 9618 Paper 1 style
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• ✓Model answer — 9618 Paper 1 style
• ✓Model answer — 9618 Paper 1 style
• ✓Model answer — 9618 Paper 1 style

Worked examples (6)

• 1Classify compression methods and examples
• 2Calculate the compression saving
• 3Apply run-length encoding to text
• 4Run-length encode a bitmap row and compare the size
• 5Justify lossy vs lossless for two situations
• 6When RLE fails and how other data is compressed

Model answers (6)

• ✓Model answer — 9618 Paper 1 style
• ✓Model answer — 9618 Paper 1 style
• ✓Model answer — 9618 Paper 1 style
• ✓Model answer — 9618 Paper 1 style
• ✓Model answer — 9618 Paper 1 style
• ✓Model answer — 9618 Paper 1 style