CAT 1991 — QA Question 43
MiscellaneousEasy
In a six-node network, two nodes are connected to all the other nodes. Of the remaining four, each is connected to four nodes. What is the total number of links in the network?
Answer & solution
Correct answer: 13
13
- B
15
- C
7
- D
26
Solution
Nodes 1 & 2 will be connected with 5 links each hence, we get 10 links
Nodes 3, 4, 5, and 6 will be connected witih 4 links each hence, we get 16 links.
Total links = 10 + 16 = 26.
Now since each link connects 2 nodes, unique number of links = 26/2 = 13.
Alternately,
(Note : In the diagram given below, the top two nodes are connected to all the other nodes, while the remaining four are connected to only four other nodes).
You find that the total number of links in the network is 13.
Hence, option (a).