Algebra math help about the rules and stuffs 10 points man!

Selena said: A square root is the same as a perfect square.
Anoop said: A cube root is always positive
Danielle said: A number is either a rational but not both.

Which students are correct? Explain why.

None are correct, but Danielle would have been correct if she hadn't left the words "or an irrational" out of her statement because a number can either be expressed as a ratio of integers (rational) or it cannot be expressed as a ration of integers (irrational). It can, or it can't, there are no other possibilities.

Selena is incorrect since the square root of a number is a perfect square only in certain cases and then only when you consider the principal square root.

Anoop is incorrect because at least one of the cube roots of any negative number will be a negative real number..