$\"\"$

The length (l) of the box is 9 inches, its width (w) is 6 inches and its height (h) is 27 inches.

The formula for the volume of rectangular prism is $\"\"$ .

Substitute the values of $\"\"$ in the formula of volume of rectangular prism.

$\"\"$

$\"\"$ . $\"\"$

The length (a) of side of the of the cube is 3 inches.

The formula for the volume of cube is $\"\"$ .

Substitute the value of $\"\"$ in the formula of volume of the cube.

$\"\"$

$\"\"$ . $\"\"$

Let x be the number of cubes.

The volume of x cubes is $\"\"$

The volume of x cubes is the the volume of rectangular box.

Therefore $\"\"$ .

Divide each side by 27.

$\"\"$

Cancel common terms.

$\"\"$ .

The number of cubes is 54. $\"\"$

The option H is correct answer.