Answer:

Step-by-step explanation:
Given


Required
Determine the difference between the points
The difference is calculated as follows:



Y = x + 5....so we sub in x + 5 for y in the other equation
4x + y = 20
4x + x + 5 = 20
5x + 5 = 20
5x = 20 - 5
5x = 15
x = 15/5
x = 3
y = x + 5
y = 3 + 5
y = 8
solution is (3,8)
To find the volume of a cone, you use the formula

.
Radius squared would be 36 in our case and 36 times 3.14 is 113.04. 6 thirds is also two, so multiply that by two and you would get 113.04 x 2 = 226.08. So, your answer would be 226.08 cubic meters of dirt.
I believe its 180.
I have seen this question before and the amount of girls was 220, so 400-220 is 180
Hope this helps :)