If the question is true or false, it is <u>false</u>. Also assuming you are referring to Excel or similar spreadsheet programs.
Answer:
Disk Operating System
Explanation:
"DOS is a platform-independent acronym for Disk Operating System which later became a common shorthand for disk-based operating systems on IBM PC compatibles."
21%4 is 1.
21-4=17
17-4=13
13-4=9
9-4=5
5-4=1