MAV 2010 Exam 2 Geometry Help

[sam.utute]

Hey guys,

I need help with question 4c in Module 2 of this exam. This is the only question that I got wrong, and I'm a little peeved. I don't understand it at all :/
The method I used was to hypothetically calculate the volume of the container, and the volume of the soil, and express it as a fraction.
I also tired using good ol' algebra.

(.5(a+b)h x l)/(.5(a+c)(h/2) x l)
= (0.5(a+c))/(a+b)
Then I substituted in for a, b and c and got
55/120 = 11/24 - Which is totally wrong.

Help is appreciated.
Sam

[sam.utute]

No replies...

My bro (math genius) said that the answer is wrong, and my solution is correct. Someone please prove him wrong.