Volume of a cube

[sjsfan01]

Can someone please help me with this problem...

The volume of a cube is equal to four times the area of one of its faces. What is the volume of the cube if one of the lengths is x inches?

I'm not understanding why the answer is 64 cubic inches.

Thank you for your help!

 

[stapel]

The volume of a cube is equal to four times the area of one of its faces. What is the volume of the cube if one of the lengths is x inches?

You started with the basics and the givens:

side length: x
volume: V = x³
area of one side: A = x²
(volume) is (four)times (area of one side): ...

What equation did you create?

I'm not understanding why the answer is 64 cubic inches.

Why? What did you get?

Please be complete. Thank you!

 

[sjsfan01]

How did they get the number 64? The area of one of its faces is x squared, right? So, 4x squared? Sorry, I'm just not seeing it.

 

[stapel]

How did they get the number 64? The area of one of its faces is x squared, right? So, 4x squared? Sorry, I'm just not seeing it.

Instead of trying to work backwards from their answer, why not try getting an answer of your own? Start with the basics and the givens, and... then what?

Please reply showing your answers to the prompts in my previous reply, continuing on to whatever answer you got. Please be complete. Thank you!

 

[sjsfan01]

Let's say that the length of one side is 3 in. That makes the volume 27 cubic inches. The problem says that the volume of a cube is 4 times the area of one of its faces. So, if one of the sides is 3 in, then the area of one of the faces is 9 square inches. I take the 9 square inches and multiply that by 4, which gives me 36 square inches. According to the problem, shouldn't I be getting 27 instead of 36?

 

[Deleted member 4993]

Let's say that the length of one side is 3 in. That makes the volume 27 cubic inches. The problem says that the volume of a cube is 4 times the area of one of its faces. So, if one of the sides is 3 in, then the area of one of the faces is 9 square inches. I take the 9 square inches and multiply that by 4, which gives me 36 square inches. According to the problem, shouldn't I be getting 27 instead of 36?

That should tell you that 3" is not the answer!

 

[Deleted member 4993]

Can someone please help me with this problem...

The volume of a cube is equal to four times the area of one of its faces. What is the volume of the cube if one of the lengths is x inches?

I'm not understanding why the answer is 64 cubic inches.

Thank you for your help!

Assume that the side of cube = x

Then

Volume of the cube V = x³

area of one face = x²

then

x³ = 4 * x²

Now solve for 'x' and then V.