Answer: The binary number system is a base-2 system that uses only two digits, 0 and 1, to represent all numbers. It is used in computers because it corresponds to the two states of electronic switches (on/off or 1/0).
Description: Computers use binary because their hardware operates with electrical signals that have two states. This system simplifies data representation and processing at the machine level.

Answer: In a computer, 1 represents an “on” state (e.g., electrical current flowing), and 0 represents an “off” state (e.g., no current). These states encode all data.
Description: The two states allow computers to store and process data efficiently using simple on/off logic, forming the basis of all digital operations.

Answer: 13 in binary is 1101.
Description: To convert: 13 ÷ 2 = 6 remainder 1, 6 ÷ 2 = 3 remainder 0, 3 ÷ 2 = 1 remainder 1, 1 ÷ 2 = 0 remainder 1. Read remainders bottom to top: 1101.

Answer: 45 in hexadecimal is 2D.
Description: Divide 45 by 16: 45 ÷ 16 = 2 remainder 13 (13 = D in hex). Result is 2D. Hex uses 0-9 and A-F (10-15).

Answer: 1010 in decimal is 10.
Description: Calculate: (1 × 2³) + (0 × 2²) + (1 × 2¹) + (0 × 2⁰) = 8 + 0 + 2 + 0 = 10.