Answer: D
154 miles.
Step-by-step explanation:
Half way is 440/2 = 220. Subtract the 66 miles already traveled, and they have 154 miles to go.
Answer:
Volume = 35185.8 
Step-by-step explanation:
Recall the formula for the volume of a cone: 
Where R is the radius of the cone's circular base (in your case half of 80 km,(that is 40 km)
And h stands for the height of the cone (in your case 21 km)
We replace such in the formula and calculate its final value:

We round it to the number of decimals your problem request (let's say to one decimal) and also include the cubic units:
Volume = 35185.8 
The new area would be 270
I believe this would be a plane
The greatest common factor between 50 and 40 is 10.