What are programs that are installed without the user knowing

There is a simple pattern for determining if a binary number is odd. what is it and why does this pattern occur? how many bits would you need if you wanted to have the ability to count up to 1000? how high could you count in binary if you used all 10 of your fingers as bits? (finger up means 1, finger down means 0)

Why should characters such as / \ " ' * ; - ? [ ] ( ) ~ ! $ { } < > # @ & | space, tab, and newline be avoided in file names?

Elements such as fonts colors visual structure graphics and the interface of a web page should complement each other to ensure blank