In the directed network diagram above, all vertices are reachable from every other vertex.

All vertices would still be reachable from every other vertex if we remove the edge in the direction from

1. `Q` to `U`
2. `R` to `S`
3. `S` to `T`
4. `T` to `R`

In the directed graph above, the only vertex with a label that can be reached from vertex Y is

1. vertex A
2. vertex B
3. vertex C
4. vertex D

Alana, Ben, Ebony, Daniel and Caleb are friends. Each friend has a different age.

The arrows in the graph below show the relative ages of some, but not all, of the friends. For example, the arrow in the graph from Alana to Caleb shows that Alana is older than Caleb.
 

 
Using the information in the graph, it can be deduced that the second-oldest person in this group of friends is

1. Alana
2. Ben
3. Caleb
4. Ebony

The following directed graph represents a series of one-way streets with intersections numbered as nodes 1 to 8.
 

 
All intersections can be reached from

1. intersection 4
2. intersection 5
3. intersection 6
4. intersection 8 

Steel water pipes connect five points underground.

The directed graph below shows the directions of the flow of water through these pipes between these points. 
 

 
The directed graph shows that water can flow from

1. point 1 to point 2.
2. point 1 to point 4.
3. point 4 to point 1.
4. point 4 to point 2.

One of the landmarks in a city is a hedge maze. The maze contains eight statues. The statues are labelled `F` to `M` on the following directed graph. Walkers within the maze are only allowed to move in the directions of the arrows.
 

1. Write down the two statues that a walker could not reach from statue `M`.   (1 mark)
   

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2. One way that statue `H` can be reached from statue `K` is along path `KFH`.
   

    

   List the three other ways that statue `H` can be reached from statue `K`.   (1 mark)
   

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