Why do computers use binary (1s and 0s) instead of the decimal system (0–9) that humans use?

Electronic circuits are naturally either on or off — binary maps perfectly to this two-state electrical reality Binary math is faster for humans to calculate mentally Binary was chosen arbitrarily by early computer scientists Binary uses less memory than decimal systems

How many different values can you represent with 3 binary digits (bits)?

8 values (000 through 111) 3 values (one per digit) 6 values (3 × 2) 16 values (including all possible combinations)

The binary number 1010 equals what decimal number?

10 2 12 4

How does a computer represent the letter 'A' in binary?

Every character is assigned a number (like 65 for 'A'), and that number is stored in binary The letter's shape is stored as a tiny image in black and white pixels Computers can't actually store letters — they convert them to sounds Letters are stored using a special alphabet code completely separate from numbers

A single bit can store how much information?

One binary digit — either a 0 or a 1 One decimal digit — a number from 0 to 9 One character of text One pixel of an image

How does a CPU execute a program instruction like 'add two numbers'?

It fetches the instruction from memory, decodes what it means, executes it in the arithmetic unit, then stores the result It sends the instruction to the hard drive to process and waits for a result It converts the instruction to a picture, then analyzes the picture It broadcasts the instruction to all RAM chips simultaneously

A digital image is made of pixels. Each pixel in a color image stores color data. How does a computer represent a red pixel?

As three numbers (red, green, blue values from 0–255) stored in binary As a wavelength of light measured in nanometers As the word 'red' encoded in ASCII characters As a single number from 1 to 100 representing color intensity

Why can't a computer run a program that is stored only on a hard drive — why must it first be loaded into RAM?

The CPU can only read instructions directly from RAM, not from the much slower hard drive Hard drives can only store data, not executable programs Programs need to be decrypted and RAM is the only place that can do this RAM is connected to the internet and programs need an internet connection to run

What is a 'multi-core' CPU?

A single CPU chip containing multiple independent processing units that can execute instructions simultaneously Multiple separate CPU chips connected by cables inside the computer A CPU that has been overclocked to run at multiple speed settings A CPU designed to handle multiple operating systems simultaneously

In the early days of computing, programs were entered using punch cards. What were punch cards?

Cards with holes punched in specific positions to represent instructions in binary — presence or absence of a hole = 1 or 0 Credit-card-sized storage devices used before USB drives existed Special cards punched by users to activate computers before keyboards were invented Cards used to punch data into early computer screens