<p>How do I do this question?</p>
<p>For any cube, if the volume is V cubic inches and the surface area is A square inches, then V is directly proportional to which of the following?
(A) A
(B) A^2
(C) A^3
(D) A^(2/3)
(E) A^(3/2)</p>
<p>The answer is E. </p>
<p>Now I am generally good at geometry and algebra, but I do not know how it is E. What is the process and how do I simplify the equation(if there is an equation)?</p>
<p>let the x be 3 </p>
<p>volume of cube = 3^ 3 = 27
the area of square = 3^ 2 = 9</p>
<p>so v is directly proportional to E </p>
<p>9 ^ 3/2 = 27</p>
<p>Let x equal one side of the cube, which is equivalent to one side of the square. Let A be the surface area of the square, & V be the volume of the cube.</p>
<p>surface area = (side of square)^2
A = x^2
A^(1/2) = x</p>
<p>The length of the side of square, x, has been found in ratio to the surface area of the square, A. Now, solve for the volume of the cube, V.</p>
<p>volumeofcube = (sideofsquare)^3
V = x^3
V = ( A^(1/2) )^3
V = A^(3/2)</p>