Answer: 14
Step-by-step explanation:
Given
Excavation cone measures
height 
Diameter 
Truck can dump
at a time
The volume of a cone is

Putting values

No of trips(N) required to accumulate this much volume is given by

Therefore, 14 trips are necessary to accumulate a cone of volume 
As already described above, the prime polynomial is that which can no longer be factored to yield a much simpler terms. From the given choices, that which cannot be factored is letter C.
1)
you have similar triangles(ABC, ADE), so their side length ratios are equal
8/2=4/CE
CE*4=4
CE=1
2)
angle bisector theorem:
CD/DA=BC/BA
CD/DA=10/8
I:AD=10CD/8
we also know AC=AD+CD=6
II:CD=6-AD
insert II in I:
AD=10(6-AD)/8
=5(6-AD)/4
=(30-5AD)/4
4AD=30-5AD
9AD=30
3AD=10
AD=10/3
8.5x-26.35=-37.35
8.5x=-37.35+26.35
8.5x=-11
X=-11/8.5
X=-1.29