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
Answer:
An alert appears on the other devices
Explanation:
On social media platforms, whenever some one make a post, all the person who are using that social media app and present in the friend circle of that particular person receive an alert containing the information of the post.
The alert that received by different users on a social media platform is known as Notification. This notification is a type of text, in which the activity performed by post creator is mentioned, this text is received with the tone called notification tone.
The purpose of the alert is to informs the friends who are using that social media platform that a post has been published by someone.