Need to translate into symbols "Someone in this class has done Data Structures”?

Question

The statements given are

1. There is someone in this class who has done Data Structures.
2. Everyone who does Knowledge Engineering does Data Structures.

my conclusion

$D=$ who does data structures

$K=$ knowledge engineering

my answer is

1. $∃x((D(x))$
2. $∀x((K(x) → D(x))$

Is my translation correct?
please help me with this one ?

Answer 1

Going off of what Mauro is saying, let's say that the universe is not the class. Since it is not the universe then let's say $C(x) = "x \text{ is in this class.}"$ Then:

$1)$ There is someone in this class who has done Data Structures. $$\exists x (C(x) \land D(x))$$ Reason: If someone is in this class then they must also have done data structures. Someone is in this class and does something. There is someone in this class and has not taken data structues.

$2)$ Everyone who does Knowledge Engineering does Data Structures.

$$\forall x(K(x)\to D(x))$$

Reason: Everyone that has done knowledge engineering also does data structures. So if you're a knowledge engineer then you do data structures.