3. Edges=n−1, where n is the number of vertices.
In other words, the number of edges is 1 less than the number of vertices.
Check each network if they fit all the categories for a spanning tree.
1st Figure
Each two vertices only has one connection and there are no loops or cycles in this network. It also has 5 edges- one less than the number of vertices, which is 6.
Therefore, this network is a spanning tree.
2nd Figure
Notice that the three vertices at the top of the network creates a cycle, and spanning trees cannot have any loops or cycles.
Therefore, this network is not a spanning tree.
3rd Figure
Each two vertices only has one connection and there are no loops or cycles in this network. It also has 5 edges- one less than the number of vertices, which is 6.
Therefore, this network is a spanning tree.
4th Figure
Each two vertices only has one connection and there are no loops or cycles in this network. It also has 5 edges- one less than the number of vertices, which is 6.
Therefore, this network is a spanning tree.
Only the 2nd figure is not a spanning tree.
Question 2 of 5
2. Question
Which of the following networks is NOT a spanning tree?
3. Edges=n−1, where n is the number of vertices.
In other words, the number of edges is 1 less than the number of vertices.
Check each network if they fit all the categories for a spanning tree.
1st Figure
Each two vertices only has one connection and there are no loops or cycles in this network. It also has 7 edges- one less than the number of vertices, which is 8.
Therefore, this network is a spanning tree.
2nd Figure
Each two vertices only has one connection and there are no loops or cycles in this network. It also has 7 edges- one less than the number of vertices, which is 8.
Therefore, this network is a spanning tree.
3rd Figure
Notice that there is a vertex that is not connected to the network, and this makes the number of edges only 6, two less than the number of vertices, which is 8.
Therefore, this network is not a spanning tree.
4th Figure
Each two vertices only has one connection and there are no loops or cycles in this network. It also has 6 edges- one less than the number of vertices, which is 7.
Therefore, this network is a spanning tree.
Only the 3rd figure is not a spanning tree.
Question 3 of 5
3. Question
Which of the following is a spanning tree from the network below?
3. Edges=n−1, where n is the number of vertices.
In other words, the number of edges is 1 less than the number of vertices.
Check each network if they fit all the categories for a spanning tree.
1st Figure
Notice that there are seven vertices that creates a cycle, and spanning trees cannot have any loops or cycles.
Therefore, this network is not a spanning tree.
2nd Figure
Notice that there are two vertices that is not connected, and vertices of a spanning trees should all be connected.
Therefore, this network is not a spanning tree.
3rd Figure
Notice that there are only eight vertices, and the given network has 9 vertices.
Therefore, this network is not a spanning tree of the given network.
4th Figure
Each two vertices are connected and there are no loops or cycles in this network. It also has 8 edges- one less than the number of vertices, which is 9.
Therefore, this network is a spanning tree.
Only the 4th figure is a spanning tree for the given network.
Question 4 of 5
4. Question
Which of the following is a spanning tree from the network below?
3. Edges=n−1, where n is the number of vertices.
In other words, the number of edges is 1 less than the number of vertices.
Check each network if they fit all the categories for a spanning tree.
1st Figure
Each two vertices are connected and there are no loops or cycles in this network. It also has 7 edges- one less than the number of vertices, which is 8.
Therefore, this network is a spanning tree.
2nd Figure
Notice that there are four vertices that is not connected, and vertices of a spanning trees should all be connected. This makes the network have 8 edges- the same count as that of its vertices.
Therefore, this network is not a spanning tree.
3rd Figure
Notice that there is a vertex that is not connected to the network and it makes the network have only 6 edges- two less than the number of vertices, which is 8.
Therefore, this network is not a spanning tree.
4th Figure
Notice that there are only seven vertices, and the given network has 8 vertices.
Therefore, this network is not a spanning tree of the given network.
Only the 1st figure is a spanning tree for the given network.
Question 5 of 5
5. Question
Which of the following is a spanning tree from the network below?
3. Edges=n−1, where n is the number of vertices.
In other words, the number of edges is 1 less than the number of vertices.
Check each network if they fit all the categories for a spanning tree.
1st Figure
Notice that there are only seven vertices, and the given network only has 6 vertices.
Therefore, this network is not a spanning tree of the given network.
2nd Figure
Notice that there are seven vertices that creates a cycle, and spanning trees cannot have any loops or cycles. This makes the network have 6 edges- the same count as that of its vertices.
Therefore, this network is not a spanning tree.
3rd Figure
Notice that there are two vertices that is not connected, and vertices of a spanning trees should all be connected.
Therefore, this network is not a spanning tree.
4th Figure
Each two vertices are connected and there are no loops or cycles in this network. It also has 5 edges- one less than the number of vertices, which is 6.
Therefore, this network is a spanning tree.
Only the 4th figure is a spanning tree for the given network.