I am in first year discrete math or key concepts is what it is called , i have a question about sets that states " suppose that $A=\{2,3,4,7\},B=\{3,7\},C=\{2,4,7\},D=\{3,5,7\}$. Determine which of these sets are subsets of which other of these sets. "
This may be a simple question for some but I am not understanding the concept and could use some help!
TIA
Basically $A \subset B $ iff $ x \in A \rightarrow x \in B $, which means "set A is a subset of B if and only if the presence of x in set A implies that x is in set B."* Can you take it from there?
*The "iff" means that if the left side is true, then the right side is true, and if the right side is true, then the left side is also true. In this case, the right side is the full statement $ x \in A \rightarrow x \in B $ which is logical implication: for this statement as a whole to be true, if $x \in A$, we must have $x \in B$; if $x \not\in A$, then x can be in B or not, it doesn't matter, and the statement is still true. Otherwise, if $x \in A$ but $x \not\in B$, the statement is false.