A rectangular prism has a length of 12 in., a width of 5 in., and a height of 414 in.


The prism is filled with cubes that have edge lengths of 14 in.


How many cubes are needed to fill the rectangular prism?

Verified Answer :

Answer:

16320 cubes are needed to fill the rectangular prism.

Step-by-step explanation:

Given : A rectangular prism has a length of 12 in., a width of 5 in., and a height of \(4\frac{1}{4}\) in.

The prism is filled with cubes that have edge lengths of \(\frac{1}{4}\) in.

To find :  How many cubes are needed to fill the rectangular prism?

Solution :

A rectangular prism has

Length of 12 in.

Width of 5 in.

Height of \(4\frac{1}{4}=\frac{17}{4}\) in.

Volume of rectangular prism is \(V=L\times B\times H\)

\(V=12\times 5\times \frac{17}{4}\)

\(V=255 in^3\)

A cube has length of \(\frac{1}{4}\) in.  

Volume of cube is \(V=L^3\)

\(V=\frac{1}{4}^3\)

\(V=\frac{1}{64}in^3\)

Cubes are needed to fill the rectangular prism is

\(=\frac{\text{Volume of rectangular prism}}{\text{Volume of cubes}}\)

\(=\frac{255}{\frac{1}{64}}\)

\(=255\times 64\)

\(=16320\)

Therefore, 16320 cubes are needed to fill the rectangular prism.

Answer:

There are needed 9 cubes.

Step-by-step explanation:

The volume of a rectangular prism is

\(V=l \times h \times w\)

Where \(l\) is the length, \(h\) is the height and \(w\) is the width.

In this case, we have

\(l=12in\\h=414in\\w=5in\)

Replacing this values we can find the volume

\(V=12in (5in)(414in)=24,840 in^{3}\)

Now, the cubes needed have edge lengths of 14 in, that means their volume is

\(V_{cube} = l^{3} =(14in)^{3}=2,744 in^{3}\)

To know how many cubes are needed, we just need to divide

\(n=\frac{24,840}{2,744} \approx 9\)

Therefore, there are needed 9 cubes.