2010 MAV GEOMETRY QUESTION :(

[physics]

The ceramic pot is in the shape of a trapezium prism. The total volume inside the pot is given by Vxm^3. Soil is put into the pot  until it is half the vertical height of the pot. What fraction of V if full of soil?

i assumed that since the soil is placed as half the height of the pot then it would be k=1/2 so therefore k^3= 1/8 but then answer...they only use k^2 =1/4

i dun understand why they use area and not volume when they ask for the volume?

[onerealsmartass]

yeah i was like wtf as well....

[sam.utute]

I had some massively long-winded working out (with squiggles) and reached the conclusion that the answer is 11/24. My bro (maths genius, finished VCE 2 years ago) came to the same conclusion. So did another one of my friends. I do not understand how they got this answer. Rubbish.

[Xavier1234]

all i got out of it was the fact that the given area ratio was the 1:2, so to get that to volume ratio, you gotta square it. it makes sense to me that way. my teacher actually contributed to that exam, and he had the same conclusion.