Question

A pile of gravel is shaped like a cone and has a radius of 6 ft and a height of 9 ft. Garden Landscaping Company purchases some of this gravel. After the gravel that Garden Landscaping Company purchases is removed, the pile has a radius of 3 ft and a height of 6 ft.

How much gravel did Garden Landscaping Company purchase?
Use 3.14 to approximate pi and express your final answer in tenths. @phi

Answer 1

I guess we have to find the volume of the starting cone as a first step.
can you do that ? I would use
volume of a cone = 1/3 * pi *r^2 *h

Answer 2

okay

Answer 3

v=1/3pir^2
v=1/3*3.14*(6)^2*(9)
v=1/3*3.14*36*9
V=1/3*1017.36
v=1017.36/3
v=339.12

Answer 4

ok
now find the volume of the small cone

Answer 5

v=1/3pir^2h
v=1/3*3.14*(3)^2*(6)
v=1/3*3.14*9*6
v=1/3*169.56
v=169.56/3
v=56.52

Answer 6

ok, they started with the big amount 339.12, and took some away.
what was left was 56.52

how much did they take away ?

Answer 7

okay do i have to subtract those two

Answer 8

if it is not clear, think about a smaller problem.
if you started with 10 marbles, and your friend took some, and now you have 1 marble, how many marbles did your friend take ?

Answer 9

oh 9 marbles

Answer 10

and how do you get 9 ? 10 - 1
big - small

use that for your problem

Answer 11

i would then get 282.6
but thing is i have to express my answer in the hundreths place

Answer 12

it says in your question
express your final answer in tenths

to be accurate to 100ths place, you should use a more exact value of pi
here we used pi = 3.14 (notice that is one more digit than 10ths)
and at the end, we round the answer to the nearest 10th

to get 100ths, we would use at least 3.142 (1 more digit than 100ths) then round at the end.

better is to use 3.14159, and then round at the end.

but, any way, your answer is ok as it is for the nearest 10th

Answer 13

oh okay thanks