Why hexadecimal is used to represent numbers, and how to convert between binary, denary and hexadecimal.

Split the 8 bits into two nibbles of 4 bits: $1100$ and $1010$.

Convert each nibble using place values $8, 4, 2, 1$: $1100 = 8 + 4 = 12$, which is C in hexadecimal; $1010 = 8 + 2 = 10$, which is A in hexadecimal.

Join the two hex digits: $\text{CA}$.

Markers reward splitting into nibbles, converting each correctly, and using the letters A to F for 10 to 15. Converting the whole byte to denary first (202) and then to hex is also acceptable if done correctly.

Reasons (one mark each, up to two): hexadecimal is more concise than binary, so long binary numbers are shorter and easier for people to read and write; it is easier to spot errors and to convert, because each hex digit maps exactly to a 4-bit nibble; and it is less prone to human mistakes than copying long strings of 1s and 0s.

Convert 2F to denary: the place values are $16$ and $1$. The digit 2 is in the 16s column ($2 \times 16 = 32$) and F is 15 in the units column ($15 \times 1 = 15$). $32 + 15 = 47$.

Markers reward two valid reasons and the correct conversion with working ($2 \times 16 + 15 = 47$).