Vivien

I actually think the factor is that ProMagma was allowed to choose a number to add to the pile.  If he didn't get to choose, I really don't know how one would get this trick to work.  Unless mindreading over computers was developed.  

Unit price is the total price of the number of items.  Simply divide \($16\) by \(5\).  You would get \(\dfrac{$16}{5}=$3.20\).

Ah.  Trick question?

You gave me 3 numbers to work with, but the answers say "squared."  I guess I am finding the area of the walls in total.

The area formula is \(bh\).  In this problem, \(b=12 \) and \(h=9\).  Each wall is \(108 ft^2\).

The room is a square (12 by 12), so all the walls' areas are the same.  So, \(108 ft \cdot\ 4 ft= \boxed{432 ft ^2}\).  The answer choice is \(\boxed{A}\).

\(3\) is a prime!  So, just \(3 \cdot\ 1\).   

So a function (?) question.  Also, it doesn't specify whether it should be an integer or not.  I'm guessing you mean an integer.  

We are told that \(x = x\) and \(y=3\).  Plug it in.

\(x\)#\(3\)\(=\dfrac{x^2}{3}\)

Also, \(x\)#\(3=9\).  Plug that in too.

\(9= \dfrac{x^2}{3}\) .  Now multiply both sides by 3 to get rid of the fraction...

\(27=x^2\).  So \(x = \sqrt{27}\).  It is also equal to \(- \sqrt{27}\).  THAT DOES NOT LOOK LIKE A NICE NUMBER.  

Unless I made a mistake which is 100% possible.