To classify the number 27 as a perfet square it would mean that if you calculate its square root the result will be a whole number.
![\sqrt[]{27}=3\sqrt[]{3}=5.19](https://img.qammunity.org/2023/formulas/mathematics/college/a24cpbtelhbzr8xwtwmdvcvplrp5sd86r1.png)
If you calculate the square root of 27 you get that it is 5.19615....., the result is not a whole number so you cant classify 27 as a perfect square.
To classify 27 as a perfect cube would mean that if you calculate the cube root of 27, the result will be a whole number:
![\sqrt[3]{27}=3](https://img.qammunity.org/2023/formulas/mathematics/college/ai0gx5sl573v0l5f93kqjybcqnow8o6kc1.png)
The result of the cube root of 27 is 3, which is a whole number, so you can classify it as a perfect cube.
The correct option is B.