Answer:
42.1558 km
Step-by-step explanation:
We know that 1 mile = 1,609 km
Then use this data as a conversion factor.
If we want to transform miles to kilometers then our conversion factor should be:

Now we must multiply the number of miles by this factori and thus we obtain the equivalent in kilometers

Using the concept of proportionality we shall solve for the unknown altitude as follows:
let the measure of the altitude be x:
24/16=x/6
solving for x we get:
x=24/16*6
x=9 feet
Answer: 9 feet
If we consider it as a combination problem, then we could calculate the how many combinations are there if we pick up three nodes out of six nodes, and then we have:

And the answer should be 20