18 x 3 = 54. So the correct answer is D. 54 pounds.
The volume will decrease.
If everything else remains the same then it will decrease. If other sides were increased proportionally then it would stay the same. It would increase if other sides were enlarged more than the length was shortened.
Answer:
24/35 or 0.6857142
Step-by-step explanation:
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 