<p>I can't solve the following problem. Help me out :)</p>
<p>16) 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?</p>
<p>A) A
B) A^2
C) A^3
D) A^ 2/3
E) A^3/2</p>
<p>Many thanks in advance :)</p>
<p>V= s^3
A= 6s^2</p>
<p>let’s solve for s in both equations.</p>
<p>V^1/3 = S
(A/6)^1/2 = S</p>
<p>V^1/3 = (A/6)^1/2</p>
<p>let’s solve for V</p>
<p>V= (A/6)^3/2
V= 1/6 x A^3/2
so, E.</p>
<p>Most of these questions can be easily solved if you substitute with numbers.
Let the side of the cube = 5 and answer it
Unless ofc. you don’t know what directly and inversely proportional mean</p>
<p>I have a feeling that solving it without substitution would be faster and easier.</p>
<p>Thank you :)</p>
<p>I am for subbing:
If the side of the cube equal 1, the volume V=1, the surface area A=6
If the side of the cube equal 2, the volume V=8, the surface area A=24.
The volume increased 8 times, the surface area - 4 times,
8=4^(3/2) - that’s E.</p>