Answer:
The function of the tab is used to advance the cursor to the next tab key.
Word processing and databases are the most common type of application software. In this case, application software, often called
productivity programs, are programs designed to specifically attain specific
tasks such as creating documents, databases, sending email, designing graphics
and even playing games. A mobile app is also an emerging type of application
software designed to run on portable devices like mobiles and PDAs. To some extent, email software is an application software
since it can also be distinguished on the basis of usage.
Each of the 20 people has 19 other people to communicate to. If you add that all up you get 20*19 paths, but then each path is counted twice (back and forth), so we divide this by 2. 20*19/2 = 190.
The general forumula is n(n-1)/2