Explanation:
Here you solve for length width and height, which multiplied equal volume. The only constant you have is that the width of the prism is 1/3 of its length.
WIDTH: 3 centimeters
LENGTH: Since the width is 1/3 of the length, 3 is 1/3 of something. So divide 3 by 1/3 to get 9. You can also just multiply 3 by 3.
HEIGHT: The height is half of the width, which is 3. Therefore 3 divided by 2 is 1.5.
Now multiply the values. 3 multiplied by 9 multiplied by 1.5
The answer is 40.5
CENTIMETERS!!!
DO NOT FORGET THE UNIT