For this case we know that we need to design a rectangular container and we have the following ratio:
lenght:width:height (5:3:2)
We also know that the total volume is given by 120 cm^3.
And we want to determine the dimensions of the container.
Step 1: Formula for the volume
Since we have a rectangular container the volume would be given by:

Where l= legth, w= width and h=height
Step 2 : Set up the formulas to use
If we select a dimension fix for example the lenght we can do the following:

The reason of this is because we have that:


Using the formula of the volume with l we can do this:
![120\operatorname{cm}^3=(6)/(25)l^3]()
Step 3: Solving for the answers
And solving for l we got:
![l=\sqrt[3]{(25)/(6)(120)}=7.937\operatorname{cm}]()
And we can find the other dimensions like this:
![w=(3)/(5)l=(3)/(5)(7.937)=4.762\operatorname{cm}]()
![h=(2)/(5)l=(2)/(5)(7.937cm)=3.1748\operatorname{cm}]()