Social Network Adjacency Analysis

00:00 4 marks

A social networking site collects data on friend connections among users. The data is represented in an adjacency matrix, where each entry \(a_{ij}\) is 1 if user \(i\) is connected with user \(j\) and 0 otherwise. Note that the matrix is symmetric and no user is friends with themselves. In a small network of 5 users, the number of friends for each user is given as follows:

– User 1: 3 friends
– User 2: 2 friends
– User 3: 4 friends
– User 4: 2 friends
– User 5: 3 friends

Determine the total number of unique connections (friendships) in the network. Provide a step-by-step explanation for your reasoning.

Hint Hint

Hint

Remember that in a symmetric adjacency matrix, each connection is counted twice, so you need to divide the total by 2.

Answer Answer
Mark Scheme Mark Scheme
Explanation Explanation
Common Errors Common Errors
Real World Context Real World Context
Focus Focus
Formula Booklet

Answer Answer

Complete Answer

Mark Scheme Mark Scheme

Answer Explanation Answer Explanation

Common Errors Common Errors

Focus Focus

Formula Booklet