The cost of fuel to propel a boat through the water (in dollars per hour) is proportional to the cube of the speed. A certain ferry boat uses worth of fuel per hour when cruising at miles per hour. Apart from fuel, the cost of running this ferry (labor, maintenance, and so on) is per hour. At what speed should it travel so as to minimize the cost per mile traveled?

The correct answer to the following question will be "V = 15 mph".

Step-by-step explanation:

According to the question,

C(V) ∝ V³

then,

C(V) = KV³

When, C = 100 and V = 10

then,

⇒        

∴  

As we know,

Total cost per hour,

C₁

Cost per mile =

Now,

C₂ =

⇒  =

Then we'll need to discover their derivative as well as set that to zero (0) to minimize it.

⇒  

⇒  

On applying cross-multiplication, we get

⇒  

⇒  

So that the cost is minimum at "V = 15 mph".

answer: h

step-by-step explanation: