# Data Representation Questions

## 2 Data Representation, exam style questions

### Binary to Denary Conversions

1. State the denary representation of the binary number `10100101` (1)
2. State the denary representation of the binary number `00101111` (1)
3. State the denary representation of the binary number `11100011` (1)
4. State the denary representation of the binary number `11110001` (1)
5. State the denary representation of the binary number `10101101` (1)

### Denary to Binary Conversions

1. State the binary representation of the denary number `42` (1)
2. State the binary representation of the denary number `97` (1)
3. State the binary representation of the denary number `128` (1)
4. State the binary representation of the denary number `200` (1)
5. State the binary representation of the denary number `247` (1)

1. State the denary representation of the hexadecimal number `42` (2)
2. State the denary representation of the hexadecimal number `A9` (2)
3. State the denary representation of the hexadecimal number `8F` (2)
4. State the denary representation of the hexadecimal number `AF` (2)
5. State the denary representation of the hexadecimal number `CC` (2)

1. State the hex representation of the denary number `42` (2)
2. State the hex representation of the denary number `97` (2)
3. State the hex representation of the denary number `122` (2)
4. State the hex representation of the denary number `201` (2)
5. State the hex representation of the denary number `248` (2)

### Binary and character encoding

1. Give one reason why we use binary to represent data in computers (1)
2. Give one reason why programmers often use hexadecimal, instead of binary, to represent numbers. (1)
3. The UTF-8 character encoding scheme can use up to 6 bytes to encode each character. How many bits is this? (1)
4. What is the total number of characters that could be encoded under the UTF-8 standard? (1)
5. Give one advantage and one disadvantage the UTF-8 character encoding scheme has over the ASCII character encoding scheme. (2)

### Sound and image representation

1. Describe how a 1 minute analogue recording of a musician playing an instrument, could be represented in binary. (3)
2. Describe how a full colour document could be represented in binary when it is scanned. (3)
3. What is meant by the term compression? (1)
4. What is the difference between lossy and lossless compression? (2)
5. Give one advantage and one disadvantage of lossy compression formats. (2)