the weight of a liquid varies directly as its volume V. if the weight of the liquid in cubical container 3 cm on a side is 54 g, find the weight of the liquid in a cubical 5 cm on a side. Ans Choices given are: 10 g; 250 g; 110 g; 125 g

Question

imstuck · Answer

Use the formula for direct variation.  In your case, it would look like this:|dw:1410969681533:dw|

imstuck · Answer

You need to plug in the first values they give you to solve for k, then plug that k back in with the other piece of info they give you to solve for what they are asking you to find.  Like this, I will show you:

imstuck · Answer

|dw:1410969781319:dw|

imstuck · Answer

Now you have your constant of variation.  Use that along with the fact that the second volume is 5, to find the corresponding weight.

emetuo89 · Answer

I got 90 i.e 18 X 5, but 90 is not part of the options.

imstuck · Answer

give me the options.  I just chose the values for y and x, but they could be the other way around.

imstuck · Answer

Your constant of variation could be .055556

imstuck · Answer

"weight varies directly as volume" is this formula: (i'm going to use W and V instead of y and x)
W = Vk
The initial weight they give you is 54, and the volume is 3, which makes the formula fill in like this:
54 = 3k
k = 18
I don't understand why it's not one of your choices; that's the formula for direct variation.  What are the choices for answers?

imstuck · Answer

Are you doing direct variation in class?